Our indigent appellant was apprehended in Fort Worth, Texas, pursuant to a warrant charging robbery of a bank in the District of Columbia. After jury trial he was convicted and sentenced to serve six to eighteen years in prison and to pay a fine of $2,000.
His chief complaint on this appeal relates to the trial court’s denial of his requests to subpoena certain witnesses in support of his various motions to exclude confessions and physical evidence obtained from him in Fort Worth.
The Government’s and appellant’s versions of the relevant facts — as developed in the pre-trial documents and trial testimony — were diametrically opposed. The Government’s testimony was that appellant, after being advised of his right to remain silent and to contact an attorney, voluntarily admitted that he had committed the crime, invited the officers to his mother’s house where he led them to the stolen money and a toy pistol, and asked to be taken to the police station where-he signed a detailed written confession. Appellant, on the other hand, testified that he was “grabbed . . . in the back of [his] pants,” threatened with physical violence, slapped in the face when he refused to confess orally, and tricked or beaten into signing the written confession; moreover, he denied consenting to the “search” of his mother’s home.
Early in the proceedings, court-appointed counsel attempted — in a variety of ways — to obtain support for appellant’s story. He requested authorization to conduct certain investigations in Fort Worth at Government expense,1 but this was denied. He moved, pursuant to Rule 15, Fed.R.Crim.P., to take depositions, at Government expense, of appellant’s sister and sister-in-law who had witnessed the search and who appellant claimed would testify that no consent was given.2 This too was denied. And he moved, pursuant to Rule 17, Fed.R. Crim.P.,3 **to subpoena, at Government expense, a number of individuals and docu*110ments, including: (1) a certain cell-mate in the Fort Worth jail who, he claimed, “could testify as to the facial appearance of the defendant after being questioned and as to the statements of the defendant after being questioned and as to the statements of the defendant that he was threatened and beaten, said statements being made while under the effects of such duress”; (2) certain newspaper reporters who, he claimed, “were let into the interrogation room immediately after the interrogation ceased and could testify as to the visual effects of the cuffing around which would indicate that any admission or confession would be involuntary”; and (3) certain records of the jail which he claimed “should have a photograph of defendant when booked that should show the effects of being cuffed around during interrogation.” This motion was also denied, on the ground that the requirements of Rule 17(b) had not been met, since “no showing [had been made] that the evidence of the witnesses is material to the defense and that the defendant cannot safely go to trial without such.”
At trial the Government produced the arresting officers from Fort Worth, each of whom testified to the Government’s version of the facts. Appellant testified to his opposing version, but without any supporting testimony or evidence. The confessions and the fruits of the “search” were ultimately admitted into evidence, and appellant was convicted.
In this appeal we face the question whether the denial of the requested subpoena was error.
An indigent defendant’s request for subpoenas is governed by Rule 17(b), Fed.R.Crim.P. It requires that each motion to subpoena a witness at Government expense be supported by an “affidavit in which the defendant shall state the name and address of each witness and the testimony which he is expected by the defendant to give if subpoenaed, and shall show that [1] the evidence of the witness is material to the defense, that [2] the defendant cannot, safely go to trial without the witness and that [3] the defendant does not have sufficient means and is actually unable to pay the fees of the witness. * * * ”
Here, appellant filed a supporting affidavit averring that the witnesses sought would corroborate his own version of the facts which, if believed, would require suppression of the confessions, the money and the gun. Thus the averments showed the materiality and necessity of the proposed witnesses’ testimony. It is apparent, however, that the trial judge construed the Rule to require that the averments be substantiated by the production of testimonial or documentary evidence.4 We disagree. We think the Rule contemplates that the required showing “that [1] the evidence is material * * * ” and “that [2] the defendant cannot safely go to trial without the witness” may rest upon averments in the supporting affidavit, as does the required showing “that [3] the defendant does not have sufficient means * * Thus if the accused avers facts which, if true, would be relevant to any issue in the case, the requests for subpoenas must be granted, unless the averments are inherently incredible on their face, or unless the Government shows, either by introducing evidence or from matters already of record, that the averments are untrue or that the request is otherwise frivolous.5
*111It follows that the court erred in denying at least some of appellant’s requests for subpoenas. We are unable to say, however, whether the error was prejudicial or harmless. Therefore, without reversing the conviction, we remand the case to the District Court with directions to determine, from evidence produced by affidavits or pursuant to procedures prescribed by Rules 15(c) and 17(b), whether the witnesses sought would have presented testimony affecting any issue in the case. If testimony affecting any jury issue (e. g., voluntariness of the confessions) would have been presented, appellant is entitled to a new trial. If testimony affecting any issue for decision by the court (e. g., Mallory6 or illegal search and seizure) would have been presented, then the witnesses will be subpoenaed for a hearing ■on any such issues and a new trial ordered if the hearing shows that evideuce admitted at trial should have been excluded.7 In the absence of such matters, the conviction will stand. Since we are remanding for a determination whether an error was harmless or prejudicial, ambiguities or uncertainties should be resolved in favor of the accused. See Kotteakos v. United States, 328 U.S. 750, 66 S.Ct. 1239, 90 L.Ed. 1557 (1946). Any determination of the trial judge will, of course, be appeal-able to this court.
So ordered.
. In support of this request, he alleged that “this case involves an arrest, search, and recovery of [stolen property] in Ft. Worth, Texas”; that “appointed counsel had been unable to perform, or have performed, any investigation involving the above events”; that “the Legal Aid Agency * * * due to the far away location of the proposed agency investigation, would be unable to authorize the same.”
. In support of these motions, he alleged that these witnesses are expected to testify “that a search took place on the premises of their abode, that the occupants of the premises did not give consent to any search, and the actions and statements at the time of the defendant and the officers involved show that the defendant did not give any consent.” He also alleged that he had written to the witnesses inquiring as to their availability and had been informed that they could not appear at the trial because “Glenda Greenwell is a teenage [sic] still in school. Virgie Greenwell is pregnant, suffers from sickness from this condition, and has a six or seven month old baby who is sickly.”
. Rule 17 provides in pertinent part:
“(a) For Attendance of Witnesses; Form; Issuance. A subpoena shall be issued by the clerk under the seal of the court. It shall state the name of the court and the title, if any, of the proceeding, and shall command each person to whom it is directed to attend and give testimony at the time and place specified therein. The clerk shall issue a subpoena, signed and sealed but otherwise in blank to a party requesting it, who shall fill in the blanks before it is served. A subpoena shall be issued by a commissioner in a proceeding before him, but it need not be under the seal of the court.
“(b) Indigent Defendants. The court or a judge thereof may order at any time that a subpoena be issued upon motion or request of an indigent defendant. The motion or request shall be supported by affidavit in which the defendant shall state the name and address of each witness and the testimony which he is expected by. the defendant to give if subpoenaed, and shall show that the evidence of the witness is material to the defense, that the defendant cannot safely go to trial without the witness and that the defendant does not have sufficient means and is actually unable to pay the fees of the witness. If the court or judge orders the subpoena to be issued the costs incurred by the process and the fees of the witness so subpoenaed shall be paid in the same *110manner in which similar costs and fees are paid in ease of a witness subpoenaed in behalf of the government.”
. This construction was particularly oppressive to appellant, since the trial court - — by denying defense requests for investigative services and depositions — had effectively precluded appellant from making the type of showing required by its construction of the Rule.
. Our construction of the Rule is consistent with Coppedge v. United States, 369 U.S. 438, 82 S.Ot. 917, 8 L.Ed.2d 21 (1962), which makes clear the duty of Federal courts “to assure to the greatest degree possible” within the framework of the relevant statutes or rules “equal treatment for every litigant” before the bar of criminal justice, regardless of financial ability. In that case the Supreme *111Court construed the statute providing that “Any court of the United States may authorize [the taking of an] appeal therein, without prepayment of * * * costs * * * ” to mean that a court of appeals must authorize the taking of an appeal unless it is so frivolous that it “would be dismissed in the case of a nonindigent litigant.” In doing so, the Court strongly intimated that a construction of the statute permitting different criteria of dismissal depending on whether the appeal was paid or in forma pauperis would run afoul of the due proc■ess proscription of unreasonable discrimination.
Rule 17 provides a different procedure for indigents and non-indigents: indigents must make the previously described judicial showing, whereas non-indigents may ■obtain subpoenas directly from the clerk’s office without averring anything. See note ■3 supra.
It is argued that there is a valid distinction between indigents and non-indi•gents in obtaining subpoenas which justifies different treatment: i. e., that there is a built-in financial “brake” on non-indigents which makes it unlikely that they will seek, at their own expense, to issue subpoenas without cause, whereas there is no such “brake” in the case of indigents whose subpoenas would be is■sued -at Government expense. In responding to the identical argument made in the context of frivolous appeals, the Supreme Court in Coppedge, supra, said that there is “no a priori justification * * * for considering [indigents’ applications] as a class to be more frivolous than those in which costs have been paid.” “ [I] f frivolous litigation exists, we are not persuaded that it is concentrated in this narrow, yet vital, area of judicial duty.” The same should be said about in forma pauperis subpoenas. If there are frivolous requests for subpoenas, the court is not powerless to control them whether they are made by indigents or non-indigents. And even if the assumption is correct that there is a greater likelihood of frivolous subpoenas by indigents, the rules should be construed to provide for no more discrimination than is necessary to protect against this assumed danger.
. Mallory v. United States, 354 U.S. 449, 77 S.Ct. 1356, 1 L.Ed.2d 1479 (1957).
. Since new evidence may be forthcoming, we do not on this appeal decide whether the facts, as developed in the present record, require exclusion of the confessions or fruits of the search under the Mallory rule.