Cozzetti was convicted of having violated 18 U.S.C. § 1952. On his direct appeal to this court, the judgment of conviction was affirmed. United States v. Cozzetti, 441 F.2d 344 (9th Cir. 1971).

Subsequently, Cozzetti filed a motion for a new trial pursuant to Rule 33, Fed.R.Crim.P. The ground of his motion, essentially, was that he had discovered new evidence which, if introduced, would reflect adversely upon the credibility of the principal prosecuting witness in the original trial. The District Court denied the motion, and Cozzetti appeals. '

A decision as to whether to grant a new trial upon the ground of alleged newly discovered evidence, which is merely cumulative or impeaching, generally rests within the sound discretion of the trial court.

“Such an allegation by the defense ordinarily will not support a motion for a new trial, because new evidence which is ‘merely cumulative or impeaching’ is not, according to the often-repeated statement of the courts, an adequate basis for the grant of a new trial.”

Mesarosh v. United States, 352 U.S. 1, 9, 77 S.Ct. 1, 5,1 L.Ed.2d 1 (1956) (footnote omitted). See also Shotwell Mfg. Co. v. United States, 371 U.S. 341, 83 S.Ct. 448, 9 L.Ed.2d 357 (1963), and our court’s decision in. Wilke v. United States, 422 F.2d 1298 (9th Cir. 1970).

The District Court also denied Cozzetti’s belated request for a disclosure of any electronic or other surveillance which had been conducted by the prosecution. This motion was properly denied, since Cozzetti offered no adequate confirmation, by affidavit or otherwise, that any such surveillance had, in fact, been conducted.

The District Court did not abuse its discretion; hence, neither of the contentions that Cozzetti now advances has merit.

Affirmed.