(dissenting).

It is the rule of Roviaro v. United States, 1956, 353 U.S. 53, 61-62 , 77 S.Ct. 623, 628 , 1 L.Ed.2d 639 that “the identity of an informer who helped set up the commission of the crime and who was present at its occurrence must be disclosed whenever the informer’s testimony may be relevant and helpful to the accused’s defense.” [emphasis added]. There, as here, the informer was a party to a transaction in which the accused allegedly sold narcotics. There, as here, the participating informer’s identity was sought in an effort to corroborate a defense of entrapment. In Roviaro the Supreme Court held that the identity of the informer must be disclosed. I am unable to agree with the majority that a difference betweeen this case and Roviaro is sufficient to warrant a different result.

The difference is that here the district court questioned the informer in camera and concluded that his testimony would not help the accused. The majority opinion recognizes that this questioning was conducted in the presence of a police officer, “was not conducted as vigorously as it might have been” and did not include questions timely filed by defense counsel for the judge’s use. I cannot be confident that such questioning provided an adequate substitute for searching pre-trial examination of the informer by defense counsel, to be followed, if the defense so desired, by testimony of the informer as a witness at trial. Where the individual whose identity is sought was a participant in and an eyewitness to the alleged criminal transaction, I would permit the concealment of his identity from defense counsel only where it appears beyond reasonable doubt that his testimony would not *9 aid the defense. In my view, the in camera examination in this ease did not satisfy that standard and thus did not justify a result different from that in Roviaro’s case.

For these reasons I would set aside this conviction and remand the case for further proceedings consistent with this opinion.