Justice Department draft documents indicate that U.S. Nazi hunters are preparing for an onslaught of criticism from conservatives and liberals as they move to deport an accused Nazi collaborator to the Soviet Union.

According to documents provided by sources in the Eastern European immigrant community, Justice Department officials have become particularly sensitive to suggestions that they are using fraudulent Soviet evidence to identify Nazi war criminals in the United States.

The documents indicate that U.S. officials fear the Soviets will stop assisting in the search for Nazis if the United States fails to deport Estonian immigrant Karl Linnas, 66. Several U.S. courts have ruled that Linnas may be deported because he told immigration officials that he was a student when, in truth, he was helping detain and murder Jews and anti-Nazis.

Linnas' family has denied the charges and argued that he has had no opportunity to confront his accusers or receive an American jury trial. In 1962, he was sentenced to death in absentia by a Soviet court whose verdict reportedly was announced three weeks before the trial.

"The Soviets want Linnas," according to what appears to be a draft memo from Assistant Attorney General Stephen S. Trott to Attorney General Edwin Meese III. "If we attempt to send Linnas somewhere else, after we have publicly designated the U.S.S.R. as the country of deportation . . . , there is a serious possibility that they may decrease their level of cooperation with OSI," the Office of Special Investigations, in charge of finding war criminals

In a brief telephone interview, Trott said the undated memo "sounds like something stolen from our offices" and "not anything that was forwarded to the attorney general." He would not discuss it further.

With some exceptions, U.S. courts have usually accepted Soviet depositions and documents as valid evidence in denaturalization and deportation cases. OSI Director Neil M. Sher has said that in West German war crimes trials, "not once to my knowledge" has a court "found that the Soviets supplied forged documents or suborned perjury."

Linnas' family and anti-communist Eastern European community groups, led by the California-based Coalition for Constitutional Justice and Security, have begun to lobby Congress and the White House to block Linnas' deportation. Former U.S. attorney general Ramsey Clark has agreed to handle Linnas' appeal of the deportation order to the U.S. Supreme Court.

John G. Healey, executive director of Amnesty International USA, has written Meese to protest the planned deportation. Healey said his organization "has grave doubts about the fairness of the trials" that sentenced Linnas and others in absentia and opposes the death penalty in all cases.

Linnas' supporters have noted that presidential assistant Patrick J. Buchanan wrote three newspaper columns harshly critical of OSI use of Soviet evidence before taking his White House post. In an interview, Buchanan said he had met with Linnas' daughter, Anu, and thought President Reagan would seek Meese's advice on whether to permit the deportation if Linnas exhausts his court appeals.

Emphasizing that it was his personal view, Buchanan said, "I think it is Orwellian and Kafkaesque to deport an American citizen to the Soviet Union to stand trial for collaboration with Adolf Hitler when the principal collaborator with Hitler in starting World War II was that self-same Soviet government."

Mari-Ann Rikken, Washington director of the Coalition for Constitutional Justice and Security, said the Linnas case "is a litmus test for both liberals and conservatives. If you're a conservative, are you as much of an anti-communist as you think you are? If you're a liberal, are you as much of a civil libertarian as you think you are?"

In his 1981 decision revoking Linnas' U.S. citizenship, U.S. District Court Judge Jacob Mishler ruled that evidence presented by federal attorneys "overwhelmingly supported" the allegation that Linnas had helped detain and kill Jews. Mishler noted that Linnas had declined to testify or appear at the denaturalization trial after he was told he could not invoke the privilege against self-incrimination in refusing to answer questions.

A May 8 decision by the 2nd U.S. Circuit Court of Appeals noted Soviet testimony that Linnas had fired into a ditch full of death camp victims and said his duties "were such as to offend the decency of any civilized society."

New York attorney Lawrence Schilling, who is now defending Linnas along with Clark and another New York attorney, Weldon Brewer, said there could have been several valid reasons for Linnas' refusal to try to contradict the Soviet evidence. He indicated Linnas will argue that the normal standards for deportation -- such as lying on his immigration application -- should not apply when he is threatened with a death sentence in a country that does not follow Western-style rules of due process.

Linnas, a retired land surveyor and former Boy Scout leader, is in a New York City jail. Justice Department officials arrested him without warning in April when he appeared at a meeting to discuss his custody status.

Anthony B. Mazeika, president of the coalition challenging the Soviet evidence and an active member of the Baltic-American Freedom League, said he thought the Soviets had singled Linnas out because of his outspoken opposition to the Soviet takeover of Estonia. In their appeal to U.S. senators, Linnas' family called him "a very young and patriotic Estonian" who served in the Estonian military, then under Nazi control, "to protect his family and homeland." "He did NOT kill Jews nor commit any Nazi atrocities," the appeal said.

The appeal expressed doubt Linnas would have been made a concentration camp chief "at the youthful age of 22" and alleged that the real commandant was a German officer, Fritz Giessen.

Anu Linnas, in an interview, said her father's legal bills had reached $300,000 before Clark recently agreed to take his case. "His whole life is ruined, everything is gone," she said.