BOSTON--Under rigorous examination from the lawyer of an accused Nazi war criminal, University Attorney Allan A. Ryan Jr. on Friday denied that he improperly prosecuted a Cleveland auto worker as death camp guard Ivan the Terrible.

Ryan, director of the Justice Department's Office of Special Investigations from 1980 to 1983, has been accused of suppressing evidence in the denaturalization trials of John Demjanjuk, who now sits on death row in Israel.

That evidence allegedly included statements by Nazi death camp guards who said Ivan the Terrible was another man, Ivan Marcenko. They said Demjanjuk was a guard at the Sobibor camp less than a hundred miles away.

Demjanjuk's attorneys and family members contend that Ryan overlooked evidence because he was under heavy political pressure to win convictions against Nazi criminals.

But Ryan, under questioning from Demjanjuk attorney Michael Tigar, repeatedly denied that he submitted to any outside pressures. He denied knowing anything of the guard statements or of Marcenko until reports from the old Soviet Union surfaced in late 1991.

"I believed the evidence showed beyond a reasonable doubt that Mr. Demjanjuk... was Ivan the Terrible," Ryan said.

Judge Thomas A. Wiseman, who presided over the case, is investigating six former and current government attorneys, including Ryan, in a special probe that will conclude Friday with the testimony of former Justice prosecutor Bruce Einhorn in Los Angeles.

Wiseman, a U.S. District Court Judge from Nashville, Tennessee, is expected to release a decision in a few weeks.

The tense proceedings focused mainly on internal Justice Department documents which were bound in three-ring binders and placed on the witness stand. Ryan frequently fumbled the volumes, and at times the binders were piled so high that members of the gallery couldn't see him.

Ryan testified that he never saw two critical memos addressed to him, which were obtained by Demjanjuk lawyers in recent months:

* A February 28, 1980 memo by former Justice lawyer George Parker expressing misgivings about the case

* A January 24, 1980 letter by Demjanjuk prosecutor Norman Moscowitz asking Ryan to question Soviet officials about Marcenko in an upcoming trip to Moscow.

Demjanjuk attorneys said they believe the Parker memo, revealed during the Parker's testimony in November, is the best evidence that Ryan and the Office of Special Investigations acted improperly in prosecuting Demjanjuk.

But Ryan said he only saw the Parker memo for the first time in October of 1992, as he was preparing to testify for Friday's bearing.

"My testimony is that if I had seen it, it would have made a very strong impression on me," Ryan said.