OPINION OF THE COURT
SEITZ, Chief Judge.The government has filed a timely appeal from a pre-trial order of the district court excluding the testimony of a government witness and any evidence derived from that witness. Our jurisdiction is based on 18 U.S.C. § 3781 (1976).
I.
In 1977, appellee Drax Quatermain agreed to assist the government in an investigation concerning the illegal manufacture of methamphetamine. Instead of receiving formal witness immunity under 18 U.S.C. § 6002 (1976), Quatermain negotiated an informal immunity agreement with government lawyers that was put in written form in a letter dated June 7, 1977. Under this arrangement, Quatermain agreed to testify in exchange for:
immunity from prosecution for your participation and involvement with Zelman A. Fairorth and others relating to the manufacture of methamphetamine.
Fairorth subsequently was convicted for illegally manufacturing methamphetamine and was sentenced to a four-year prison term.
While on bail pending appeal, Fairorth became an informant against Quatermain in connection with a government investigation of Quatermain’s alleged illegal manufacture of a gun silencer. This illegal conduct allegedly occurred in July and August of 1978, thirteen or fourteen months after Quatermain entered into the immunity agreement relating to the methamphetamine investigation. The government concedes that Fairorth’s cooperation was motivated, at least in part, by Quatermain’s prior testimony against him. Fairorth bought, with government funds, the materials needed to make a silencer and delivered them to Quatermain. Based on evidence obtained from Fairorth, Quatermain was indicted for possession of a firearm by a person previously convicted of a felony and for four other offenses relating to the manufacture, possession, and transfer of the silencer.
*40On November 22, 1978, Quatermain filed a motion to dismiss the indictment, alleging that it was based almost entirely on evidence obtained from Fairorth and that such evidence was derived from Quatermain’s prior testimony against Fairorth in violation of the immunity agreement. Because the district court could not determine from the record before it what evidence the grand jury had relied on in returning the indictment, it treated the motion to dismiss as a motion to suppress Fairorth’s testimony and any evidence derived from that testimony. It held that Fairorth’s testimony was derived from Quatermain’s prior cooperation with the government and ordered the testimony and all evidence derived from it excluded. The government subsequently filed the present appeal.
II.
Much of the controversy before the district court centered on the meaning of the immunity agreement between Quatermain and the government that granted Quatermain “immunity from prosecution” for his involvement with Fairorth “relating to the manufacture of methamphetamine.” Witness immunity generally is characterized as either transactional immunity or use and derivative use immunity. Transactional immunity “accords full immunity from prosecution for the offense to which the compelled testimony relates.” Kastigar v. United States, 406 U.S. 441, 453, 92 S.Ct. 1653, 1661, 32 L.Ed.2d 212 (1972). Use and derivative use immunity prohibits the use of compelled testimony or any evidence derived from that testimony against the witness in a criminal prosecution. See id. at. 452-53, 92 S.Ct. 1653. Under this latter type of immunity, the witness still may be prosecuted for crimes about which he testifies if the government proves that it has other evidence that is derived from a source wholly independent of the compelled testimony.
Quatermain argued in the district court that his immunity agreement granted use and derivative use immunity. The government’s position is more difficult to ascertain. ■ It characterized the immunity as both transactional and use immunity, but asserted that whatever title was used, the immunity was limited to immunity from prosecution for Quatermain’s participation in the manufacture of methamphetamine.
The district court found that the immunity agreement was ambiguous on its face and therefore considered the context surrounding the agreement to interpret its meaning. The court relied on several factors in making its decision. First, it found no evidence that Quatermain had been informed of the scope of his fifth amendment privilege against self-incrimination or that he had knowingly and intelligently waived it. Second, it noted that Quatermain was not represented by counsel when he negotiated the immunity agreement with government lawyers. Third, the agreement gave Quatermain “immunity from prosecution” without specifically excluding use and derivative use immunity. Finally, it relied on the fact that the government had referred to the immunity as use immunity in its answer to the motion to dismiss and had refused to withdraw this characterization when questioned in open court.
Based on these considerations, the district court found that Quatermain agreed,to testify in exchange for the minimum immunity required by the Constitution to compel a witness to testify. Relying on the Supreme Court’s holding in Kastigar v. United States, 406 U.S. 441, 92 S.Ct. 1653, 32 L.Ed.2d 212 (1972), that use and derivative use immunity was constitutionally sufficient- to compel testimony over a claim of the privilege against self-incrimination, the district court concluded that Quatermain had been granted use and derivative use immunity.
On this appeal, the government argues that Quatermain’s testimony against Fairorth was not compelled because Quatermain volunteered to help the government in its methamphetamine investigation. Therefore, it contends that use and derivative use immunity is not required in this case by the fifth amendment, which prohibits only the use of compelled testimony, see Fisher v. *41United States, 425 U.S. 391, 397, 96 S.Ct. 1569, 48 L.Ed.2d 39 (1976), and that the district court erred in finding the immunity agreement granted the constitutional minimum. It argues that the immunity conferred in this case was narrower, limited to immunity from prosecution for participation in the methamphetamine scheme.
In view of our conclusions, however, we deem it unnecessary to decide whether, under the procedure used by the government here, Quatermain’s testimony was in any way compelled or whether he knowingly and intelligently waived his privilege against self-incrimination by agreeing to testify in exchange for immunity that was not commensurate with his fifth amendment privilege. Instead, we will assume, without deciding, that the district court correctly found that the informal agreement conferred the minimum immunity required by the Constitution to compel a witness’s testimony after the witness has claimed the privilege. Therefore, we now must consider whether it follows from this assumption that Fairorth’s testimony and evidence derived from it must be excluded in this case.
III.
After holding that the immunity agreement conferred use and derivative use immunity on Quatermain, the district court concluded that Fairorth’s testimony against Quatermain was a derivative use of Quatermain’s immunized testimony because it was motivated, at least in part, by Quatermain’s previous testimony that had resulted in Fairorth’s conviction. See United States v. Kurzer, 534 F.2d 511 (2d Cir. 1976). Therefore, it ordered the exclusion of Fairorth’s testimony.
The government does not contest the district court’s finding that Fairorth’s testimony was motivated by Quatermain’s prior cooperation with the government in its prosecution of him. However, it contends that the district court improperly extended the scope of the immunity granted in this case. It argues that the scope of Quatermain’s fifth amendment privilege against self-incrimination does not extend to crimes that he might commit in the future and that are unrelated to his prior immunized testimony. Therefore, it asserts that the immunity given Quatermain, which was granted to remove the danger of self-incrimination, did not require exclusion of Fairorth’s testimony relating to the manufacture of the silencer.
In Kastigar v. United States, 406 U.S. 441, 92 S.Ct. 1653, 32 L.Ed.2d 212 (1972), the Supreme Court held that to compel testimony over a claim of the privilege against self-incrimination, “a grant of immunity must afford protection commensurate with that afforded by the privilege, [but] it need not be broader.” Id. at 453, 92 S.Ct. at 1661. The Court upheld the constitutionality of the federal immunity statute, see 18 U.S.C. § 6002 (1976), which provides for use and .derivative use immunity, because it found that “such immunity ... is coextensive with the scope of the privilege against self-incrimination.” 406 U.S. at 453, 92 S.Ct. at 1661.
We are not presented in this case with the question whether a grant of use and derivative use immunity can afford a witness protection against self-incrimination that is broader than the protection provided by the constitutional privilege because here the district court construed the parties’ agreement to confer the minimum immunity required by the Constitution. Under this construction, the purpose of the grant of immunity was to afford protection against self-incrimination to the same extent as the fifth amendment privilege. Therefore, the immunity granted in this case is limited by the scope of the privilege. If Quatermain could not have invoked the privilege when he testified against Fairorth on the ground that Fairorth might testify against him concerning crimes that might be committed in the future, then the immunity granted here does not preclude use of Fairorth’s testimony against Quatermain.
The Supreme Court on many occasions has stated that the purpose of the privilege against self-incrimination is “ ‘to insure that a person should not be compelled, when acting as a witness in any *42investigation, to give testimony which might tend to show that he himself had committed a crime.’ ” Lefkowitz v. Turley, 414 U.S. 70, 77, 94 S.Ct. 316, 322, 38 L.Ed.2d 274 (1973) (quoting Counselman v. Hitchcock, 142 U.S. 547, 562, 12 S.Ct. 195, 35 L.Ed. 1110 (1892) (emphasis added)). Thus, the privilege usually applies to prohibit testimony that might incriminate a witness for past crimes. See Rule v. United States, 362 F.2d 215, 217 (5th Cir. 1966), cert. denied, 385 U.S. 1018, 87 S.Ct. 744, 17 L.Ed.2d 554 (1967).
In Marchetti v. United States, 390 U.S. 39, 88 S.Ct. 697, 19 L.Ed.2d 889 (1968), however, the Court held that the privilege was not entirely inapplicable to prospective acts. There, the defendant was convicted for violating federal wagering tax statutes due to his failure to pay an occupational tax and to register with the government before engaging in the business of accepting wagers. He argued that the statutory obligations to pay the tax and to register increased the likelihood of prosecution for future gambling activity.
The Court rejected the premise that the privilege against self-incrimination applied only to prior conduct and held that:
The central standard for the privilege’s application has been whether the claimant is confronted by substantial and “real,” and not merely trifling or imaginary, hazards of incrimination.
Id. at 53, 88 S.Ct. at 705. Although it recognized that “prospective acts will doubtless ordinarily involve only speculative and insubstantial risks of incrimination,” id. at 54, 88 S.Ct. at 705, it found that the hazard of incrimination created by the tax statutes was substantial because the information derived from the statutory requirements “may serve as decisive evidence that [registrants] have in fact subsequently violated state gambling prohibitions.” Id.
The Court emphasized the narrowness of the privilege’s application to future conduct in United States v. Freed, 401 U.S. 601, 91 S.Ct. 1112, 28 L.Ed.2d 356 (1971). In that case the Court upheld the constitutionality of provisions of the National Firearms Act that required registration of a firearm before it could be transferred to a new owner. The statute in question provided that no information produced by compliance with the Act could be used in a criminal proceeding relating to a prior or concurrent violation of the law. Id. at 604, 91 S.Ct. 1112. Based on this statutory immunity and the practice of not making registration data available to other federal or state agencies, the Court held that the defendant was not confronted by any “substantial and real” hazard of incrimination. In response to the defendant’s claim that the disclosure required by the statute might incriminate him in the future, the Court concluded that this argument:
assumes the existence of a periphery of the Self-Incrimination Clause which protects a person against incrimination not only against past or present transgressions but which supplies insulation for a career of crime about to be launched. We cannot give the Self-Incrimination Clause such an expansive interpretation.
Id. at 606-07, 91 S.Ct. at 1117.
We think that the present case is distinguishable from Marchetti and does not fit within the narrow category of cases where the privilege against self-incrimination permits a witness to refuse to testify because of the possibility that such testimony will incriminate the witness concerning future criminal conduct. The Court found a “substantial and real” risk of incrimination in Marchetti because the information required by the wagering statute significantly enhanced the likelihood of the registrant’s prosecution for future gambling activities. The future conduct involved there was part of a continuing course of similar criminal activity. The subsequent offense in this case, however, was not the result of a continuous criminal enterprise and involved a different type of criminal activity.
Quatermain has cited no cases, and our research has revealed none, where the fifth amendment privilege against self-incrimination has been held to apply to a witness who refuses to testify because he asserts that his testimony somehow may be used to *43incriminate him in a prosecution for a different type of criminal act that he may commit in the future. Indeed, two courts have rejected similar claims, finding that the hazard of incrimination arising from one’s possible commission of a wholly different criminal act at some time in the future is too speculative and remote to merit fifth amendment protection. See Desimone v. United States, 423 F.2d 576, 581-82 (2d Cir.), cert. denied, 400 U.S. 842, 91 S.Ct. 84, 27 L.Ed.2d 77 (1970); Varitimos v. United States, 404 F.2d 1030, 1034 (1st Cir. 1968), cert. denied, 395 U.S. 976, 89 S.Ct. 2126, 23 L.Ed.2d 765 (1969).
Therefore, we find that Quatermain could not have relied on the privilege against self-incrimination to refuse to testify about Fairorth’s involvement in the illegal manufacture of methamphetamine on the ground that the testimony given might incriminate him if he committed a different type of crime in the future. Because the privilege against self-incrimination does not extend to such future conduct and because the district court held that the parties' informal immunity agreement granted Quatermain the minimum immunity required to protect his constitutional privilege, the immunity granted Quatermain necessarily does not preclude use of Fairorth’s testimony against Quatermain in the prosecution for offenses relating to the manufacture of the silencer.
IV.
The order of the district court, which treated Quatermain’s motion to dismiss the indictment as a motion to suppress evidence, will be reversed.
After the district court entered the order here appealed, but before this appeal was filed, it entered another order dismissing the indictment because the government could not proceed without using evidence obtained from Fairorth. It is not clear to us why the government did not appeal this latter order. Nevertheless, in light of our disposition of this appeal, we assume that the government will make an appropriate application in the district court with respect to the order dismissing the indictment.