University Attorney Allan A. Ryan Jr. will answer charges Friday that he suppressed evidence in the trial of Cleveland autoworker John Demjanjuk, accused of being the Nazi death camp guard "Ivan the Terrible."

Ryan, the former director of the Justice Department's Office of Special Investigations, will answer questions from Demjanjuk's attorneys and U.S. District Judge Thomas A. Wiseman in a federal courtroom in Boston.

Wiseman, a Tennessee-based judge, is conducting a probe of six former and current government attorneys, including Ryan.

Demjanjuk was convicted and extradited to Israel in 1986, where he sits on death row. Demjanjuk's attorneys have alleged that Ryan and other Justice officials suppressed evidence that suggested that a person named Ivan Marcenko, and not Demjanjuk, was the real "Ivan the Terrible."

The investigation was prompted last year by new evidence from records of the former Soviet Union indicating that Demjanjuk was a guard at the Sobibor camp and not at Treblinka, where "Ivan" was posted.

Ryan, who came to the University in 1985, has repeatedly refused to comment on the probe, saying the case hasnothing to do Harvard University.

Ryan did not return a phone call yesterday.

George Parker, a former government prosecutor,testified last November that Ryan rebuffed himwhen he expressed doubts about the government'sevidence against Demjanjuk.

The four previous witnesses in the casetestified in Nashville. Ryan had been expected togo to Tennessee last month, but his hearing wasdelayed and moved to Boston.

Next week, Wiseman will fly to Los Angeles tospeak with former Justice employee Bruce J.Einhorn, now a judge in California