The appellant, George F. Brown, was indicted by a Federal Grand Jury in Baton Rouge, Louisiana for receiving $15,000 from Dixie Brewing Company in 1974 and $15,-000 from Falstaff Brewing Company in 1975, in connection with the passage of legislation by the Louisiana Legislature favorable to breweries, and failing to report such payments on his income tax returns, all in violation of 26 U.S.C. § 7206(1).1
Appellant was not a member of the Legislature, but was the Executive Director of the Beer Industry League of Louisiana and, as such, was in a position to influence legislation relative to breweries. These payments were first investigated by a Federal Grand Jury in New Orleans in connection with a conspiracy indictment (not involved in this appeal) returned against appellant and others. Later, the Government sent an agent before a Federal Grand Jury in Baton Rouge who summarized the evidence presented to the Grand Jury in New Orleans. No other witness appeared before the Baton Rouge Grand Jury. Thus, the indictment in the instant case was based solely on hearsay testimony, which is one of the circumstances complained of by appellant in this appeal.
The appellant was tried before a jury on a two-count indictment involving the two payments, and was found guilty on both counts by the jury. He was sentenced by the court on each count to a term of three years on condition that he be confined in a jail-type institution for 180 days, with suspension of the remainder of the sentence, to be followed by probation for 3 years beginning with his release from confinement, the sentences to run concurrently. The appellant then appealed to this court. We affirm, subject to the remand of a part of the case to the trial court with instructions, as set forth below.
The appellant filed pre-trial motions for discovery and to dismiss the indictment in which he complained of the indictment being based on hearsay evidence, and also alleging that the integrity of the grand jury proceedings had been impaired by the following incidents and circumstances:
(1) Failure to advise indicting grand jury that the witness Gregg had given inconsistent testimony in his two appearances before earlier grand jury in New Orleans;
(2) Failure to advise grand jury that the witnesses whose statements had been summarized before them had been immunized;
(3) That the summarized witnesses’ statements did not support the facts alleged in indictment, and;
(4) That no substantial evidence was presented to grand jury to warrant the indictment.
The court issued a Reciprocal Uniform Discovery Order but denied the motion to dismiss the indictment.
Appellant’s argument that the indictment should be dismissed because it is based on hearsay evidence is unpersuasive. By its very nature, the grand jury process is not an adversary proceeding. Its function is merely to determine if there is probable cause which warrants the defendant’s being bound over for trial. A defendant has no right to require that the Government present all available evidence at this proceeding. The grand jury proceeding is a one-sided affair. The defendant is protect*1276ed from such one-sidedness when, at the trial on the merits, he is “accorded the full protections of the Fifth and Fourteenth Amendments” and is “permitted to expose all of the facts bearing upon his guilt or innocence.” United States v. Chanen, 549 F.2d 1306, 1311 (9 Cir. 1977).
Our decision in United States v. Cruz, 478 F.2d 408 (5 Cir. 1973) is dispositive of this argument. In that case we held that an indictment based on hearsay evidence is valid, saying:
“Grand Jury Hearsay
The appellants contend that their grand jury indictment was invalid because it was based on the hearsay testimony of one investigating FBI officer rather than on direct testimony of informant-witnesses whom the government could have summoned to testify. In Costello v. United States, 350 U.S. 359, 76 S.Ct. 406, 100 L.Ed. 397 (1956), the Court considered and rejected the contention that an indictment based exclusively on hearsay evidence is constitutionally invalid. This reasoning has been followed on many occasions by this court. See, e. g., United States v. Bird, 456 F.2d 1023 (5th Cir. 1972); United States v. Klaes, 453 F.2d 1375 (5th Cir. 1972); United States v. Howard, 433 F.2d 1 (5th Cir. 1970), cert. denied, 401 U.S. 918, 91 S.Ct. 900, 27 L.Ed.2d 819 (1971).”
“While the presentation of hearsay testimony of an investigating officer in lieu of readily available testimony by direct witnesses is by no means a preferred procedure, it is neither unconstitutional nor inherently wrong. In the absence of some showing that the integrity of grand jury proceedings has been impaired, an indictment even if based exclusively on such testimony will not be overturned on appeal.” 478 F.2d 410-411.
We hold that the trial court did not abuse his discretion in denying appellant’s Motion to Dismiss the indictment even though it was based exclusively on hearsay evidence.
The complaint of appellant that the failure to advise the indicting grand jury that the witness Gregg had given inconsistent statements to another grand jury, and that witnesses whose statements were summarized for the grand jury had been granted immunity, bear on the credibility of such witnesses and is without merit. The Government is under no duty to present to a grand jury evidence bearing on the credibility of witnesses. This very question was decided adversely to appellant’s contention by the Ninth Circuit Court of Appeals in United States v. Chanen, 549 F.2d 1306, 1311 (9 Cir. 1977) in which the court held;
“In Loraine v. United States, 396 F.2d 335 (9th Cir.), cert. denied, 393 U.S. 933, 89 S.Ct. 292, 21 L.Ed.2d 270 (1968), the defendant moved to dismiss the indictment on grounds that the prosecutor, in his presentation to the grand jury, wilfully suppressed evidence that would undermine the credibility of three crucial witnesses before the grand jury. Apparently, one witness had a criminal record and was then under indictment in several other cases; another witness had been charged with embezzlement; the last had been enjoined from dealing in securities. We held that
‘the trial court did not err in refusing to invalidate a federal indictment because the Government did not produce before the grand jury all evidence in its possession tending to undermine the credibility of the witnesses appearing before that body. Loraine was accorded the full protections of the Fifth and Fourteenth Amendments, when, at the trial on the merits, he was permitted to expose all the facts bearing upon his guilt or innocence.’ ”
In the instant case, appellant was furnished a list of all the witnesses, except Gregg, who had been granted immunity, two months before the trial. There was some evidence that appellant knew before the trial began that Gregg had been granted immunity. In any event, appellant knew of his immunity during the trial and thoroughly cross-examined him with reference to it. As to Gregg’s prior inconsistent *1277statements, appellant had every opportunity to present them to the jury and, in fact, did so. Appellant has not shown that he was prejudiced by the foregoing incidents. We find no error in this phase of the case. The appellant was given the full protections of the Fifth and Fourteenth Amendments when he was allowed to develop at the trial all of the facts bearing on his guilt or innocence.
Appellant’s arguments that the summarized statements of the witnesses did not support the facts alleged in the indictment, and that no substantial evidence was presented to the grand jury to warrant the indictment, are unpersuasive. In United States v. Cruz, supra, we held:
“Taking a different approach, the appellants argue that their indictments were invalid because the grand jury did not have before it any probative evidence, either hearsay or direct, upon which to base the indictments. However, the majority opinion in Costello also squarely rejected the contention that appellate courts may review the sufficiency of evidence supporting an indictment. 350 U.S. at 363, 76 S.Ct. at 408-409. The appellants’ reliance on the concurring opinion of Mr. Justice Burton in Costello and on dicta in the pre-Costello opinion of this court, Friscia v. United States, 5 Cir., 63 F.2d 977, 980, cert. denied, 289 U.S. 762, 53 S.Ct. 797, 77 L.Ed. 1505 (1933), is misplaced. We will not review the sufficiency of the evidence, if any, supporting the grand jury indictments in this case. See Cohen v. United States, 436 F.2d 586 (5th Cir.), cert. denied, 403 U.S. 908, 91 S.Ct. 2215, 29 L.Ed.2d 684 (1971); United States v. Gower, 447 F.2d 187 (5th Cir.), cert. denied, 404 U.S. 850, 92 S.Ct. 84, 30 L.Ed.2d 88 (1971).” 478 F.2d 408 at 412.
See also United States v. Calandra, 414 U.S. 338, 344-345, 94 S.Ct. 613, 38 L.Ed.2d 561 (1974); United State v. Boerner, 508 F.2d 1064, 1068 (5 Cir. 1975); and United States v. Newcomb, 488 F.2d 190, 192-193 (5 Cir. 1974).
Accordingly, we will not review the sufficiency of the evidence before the grand jury on which the indictment was based.
The appellant complains that the court erred in refusing to grant a mistrial or a continuance at the beginning of the trial based on the fact that he was not furnished a transcript of his testimony and that of certain prospective Government witnesses before the grand jury until two days before the trial. Even if the transcript should have been furnished to him earlier, appellant has not shown that he was prejudiced thereby. This is especially true since the Government did not use the transcript at the trial.
As stated above, the trial court issued a Reciprocal Uniform Discovery Order prior to the beginning of the trial. This order compelled disclosure of “all exculpatory evidence within the meaning of Brady v. Maryland, 373 U.S. 83, 83 S.Ct. 1194, 10 L.Ed.2d 215 (1963) and Giles v. Maryland, 386 U.S. 66, 87 S.Ct. 793, 17 L.Ed.2d 737 (1967).” Appellant sought to supplement the order by written motion requesting that he be furnished with:
“3. The materials contained in the files of the Internal Revenue Service relative to its investigation of defendant for the calendar years 1974 and 1975 which negate or which may tend to negate the receipt of unreported income by the defendant in the amounts alleged in the indictment. Included in this request are materials relative to any net worth analysis by Internal Revenue Service and the reports of its agents as to defendant’s spending habits.
“4. Any materials reflecting the name and current address of, and/or any statements of the Internal Revenue Service in connection with its investigation of defendant’s 1974-1975 income tax returns, who either (1) was not called or put before the Grand Jury or (2) was called before the Grand Jury but will not be called as a witness at the trial.”
The government answered this motion urging that this and other information sought is “beyond the scope of F.R.Cr.P. Rule 16 or has already been ordered dis*1278closed." This motion was denied by the court. Appellant later urged substantially the same matters in a Motion to Dismiss, which was also denied. The appellant says that the court erred in denying these motions because the material he sought would have given him a “clean bill of health.” He contended throughout the trial that the Falstaff and Dixie Brewing Companies that made the payments to him never intended that he was to receive any economic benefit from the money so paid, and that in fact he received no economic benefit therefrom.2 The Government refused to furnish appellant any part of the Internal Revenue Service audit, saying that it was not relevant and the appellant was, therefore, not entitled to it.
The Government contends on this appeal that a substantial omission of income from his tax return by the appellant constituted a “material matter” within the contemplation of 26 U.S.C., § 7206, citing Hoover v. United States, 358 F.2d 87 (5 Cir. 1966), and that in a prosecution under the statute the lack of a tax deficiency is neither essential nor relevant, citing United States v. Jernigan, 411 F.2d 471, 473 (5 Cir. 1969), cert. denied 396 U.S. 927, 90 S.Ct. 262, 24 L.Ed.2d 225, and Shepps v. United States, 395 F.2d 749 (5 Cir. 1968), cert. denied 393 U.S. 925, 89 S.Ct. 256, 21 L.Ed.2d 261.
The Supreme Court and this court have held:
“ . . . it is the power to dispose of income and the exercise of that power that determines whether taxable income has been received. Helvering v. Horst (1940) 311 U.S. 112, 61 S.Ct. 144, 85 L.Ed. 75; Floyd v. Scofield, 5th Cir. 1952, 193 F.2d 594.” Sammons v. United States (5th Cir. 1970) 433 F.2d 728 at 732.
See also Corless v. Bowers, 281 U.S. 376, 50 S.Ct. 336, 74 L.Ed. 916 (1930), and Rutkin v. United States, 343 U.S. 130, 72 S.Ct. 571, 96 L.Ed. 833 (1952).
In the instant case, the trial court charged the jury:
“The test is whether or not the money was received together with unfettered control over the disposition of that money.”
The appellant did not object to this charge. The Government says that the charge complies with the law and that the I.R.S. audit was not material or relevant to guilt or punishment. We cannot say in the present state of the record whether or not this is true, because we do not know what is contained in the audit. Evidence that is “material either to guilt or to punishment” should be disclosed under the “Brady rule.’’ See Moore v. Illinois, 408 U.S. 786, 794, 92 S.Ct. 2562, 33 L.Ed.2d 706 (1972). The test for materiality of such evidence is whether the evidence “might have affected the outcome of the trial.” United States v. Agurs, 427 U.S. 97 at 110, 96 S.Ct. 2392, 2400, 49 L.Ed.2d 342 (1976). Since the contents of the audit were not revealed to the trial judge, there was no way that he could determine whether it contained exculpatory evidence that was material to guilt or to punishment in a way that might have affected the outcome of the trial. The Government argues that the appellant’s net worth analysis and spending habits information would not have negated or tended to negate his receipt of unreported income.3 This question should have been determined by the trial court only after he had examined and considered the contents of the audit. It is obvious that neither the trial court nor this court can decide cases in a vacuum, nor pass on facts that are not in the record.
We conclude that this case cannot be properly disposed of until the contents of the I.R.S. audit are revealed to the trial court in an in camera inspection and he has made findings and conclusions as to whether the audit contains exculpatory evidence that is material to the guilt or to the punishment of appellant, and which might have *1279affected the outcome of the trial. This part of the case is remanded to the trial court for this purpose. We affirm the trial court’s judgment as to the rest of the case.
The trial court is directed to make such in camera examination of the I.R.S. audit of appellant’s tax records for 1974 and 1975, and in the event the court finds and concludes that the audit contains exculpatory evidence that is material to the guilt, or to the punishment of appellant, and which might have affected the outcome of the trial, the court is authorized and directed to take appropriate action in the case.
On the other hand, if the court finds and concludes that the audit does not contain such exculpatory evidence, he is authorized and directed to enter an order on the mandate affirming the judgment of conviction and sentence of appellant by the trial court.
AFFIRMED in part and REMANDED in part to the Trial Court with instructions.
. 26 U.S.C., § 7206(1) provides:
“§ 7206. Fraud and false statements Any person who—
(1) Declaration under penalties of perjury.— willfully makes and subscribes any return, statement, or other document, which contains or is verified by a written declaration that it is made under the penalties of perjury, and which he does not believe to be true and correct as to every material matter; . . . shall be guilty of a felony and, upon conviction thereof, shall be fined not more than $5,000, or imprisoned not more than 3 years, or both, together with the costs of prosecution. Aug. 16, 1954, c. 736, 68A Stat. 852.”
. The appellant did not testify, and there is no evidence who, if anyone, received an economic benefit from the payments.
. The Government admits that such evidence might be exculpatory in a prosecution under 26 U.S.C., § 7201 for attempted tax evasion.