State Department officials smuggled more than 300 Russian-born Nazi collaborators into the United States after World War II and helped them become U.S. citizens and obtain jobs in return for their participation in Soviet spying operations during the Cold War, the CBS television program "60 Minutes" reported yesterday.

The smuggling proceeded despite orders by Presidents Franklin D. Roosevelt and Harry S. Truman barring immigration of Nazi war criminals, and intelligence agencies continued to cover it up as recently as 1978 during a congressional investigation, according to a former Justice Department prosecutor interviewed on the program.

"We had one unit of the government out trying to prosecute the Nazis and other units of the government trying to secret the information," said John Loftus, a Boston attorney who left the Justice Department's Office of Special Investigations last year. President Carter created the office in 1980 to root out Nazi war criminals hiding in the United States.

"We later established that the files pertaining to the Nazi immigration had been withheld from Congress, from the courts, from the CIA and from the local agents of the Immigration Service," Loftus said.

Rep. Barney Frank (D-Mass.) of the House Judiciary Committee said yesterday he plans to call for an investigation of the smuggling campaign and the alleged cover-up. He said Loftus showed him classified documents that convinced him Congress was told "flat lies" when it asked the Army in 1978 for information on 111 alleged Nazi war criminals living in the United States.

The Army responded that it had found no files on many of the suspected collaborators.

"I don't want to surp the role of the Justice Department, but I think they need the help of Congress," Frank said, "The role of Congress is to make sure that elements in the Pentagon or within the intelligence agencies don't bureaucratically frustrate justice from doing its jobs."

The existence of the smuggling campaign is apparently still hindering efforts by the Justice Department to deport Nazi war criminals living in the United States. In deportation proceedings, the department generally seeks to prove that suspects concealed their collaboration with the Nazis, a spokesman said. The department threw out a 1980 case against Tscherim Soobzokov, a Russian-born Nazi commander living in Paterson, N.J., after the CIA revealed that it knew of his past.

Loftus said he saw classified information while working for Justice that indicated the smuggling program was approved "at the highest levels." It was carried out by the Office of Policy Coordination which was run by the late Frank Wisner under the Office of Strategic Services, and involved the FBI, Army Counterintelligence and Army Foreign Intelligence, Loftus told "60 Minutes."

"They knew that the entire Nazi government of Byelorussia, the president, the vice presidents, cabinet ministers, governors and mayors, police chiefs were all living in America," Loftus said of the intelligence agencies.

Spokesmen for the Defense and State departments and the FBI had no comment yesterday on the accusations. A spokesman confirmed that the Justice Department is "aware of these allegations and is looking into them."

Loftus estimated that more than 300 Nazi collaborators from the Soviet republic, Byelorussia, are still living in this country, and some are still working for the government and quasi-governmental groups, he said.

Officials of Radio Free Europe/Radio Liberty confirmed in interviews with The Post that several suspected collaborators named in the "60 Minutes" broadcast worked there, but were believed to have been cleared by the federal government.

One of them, Stanislau Stankevitch, a former freelancer for the radios who died recently, was in charge of large-scale exterminations of Jews in Byelorussia, Loftus said. Loftus said his office had prepared a case "containing his confessions, his admissions of Nazi background," but Stankevich died before he was prosecuted.

Stankevitch was apprehended by U.S. Army Counterintelligence in a displaced persons camp in 1948, after working for the Soviets, the Nazis and then the Soviets again, Loftus said. But he was smuggled into the United States as an informant and propagandist against the Soviet Union, rather than being prosecuted, Loftus said.

"He was very well known as a collaborator," said Anton Adomovitch, a staff writer and co-worker of Stankevitch's, who also worked for the radio programs that broadcast programs behind the Iron Curtain.

In a telephone interview with The Post from his New York home, Adomovitch, 73, said he was himself a newspaperman for the Nazi-controlled press in Byelorussia and later an editor of Nazi publications in Berlin.

"In the sense that I worked for a newspaper during the Nazi time, yes, I was a collaborator , but not in the sense of my soul," Adomovitch said.

"The American authorities knew everything about my background," Adomovitch said, referring to his emigration to the United States in 1950. He said the OSS contacted him in Berlin after the war, and enlisted him in Soviet intelligence-gathering.

Once granted U.S. citizenship in 1955, Adomovitch said he became a Soviet informant for the FBI. "When I had something, I got in touch with them," he said. For example, Adomovitch said, he passed along inside information about Soviet-Cuban relations in the 1960s from a Russian contact.

Officials of Radio Free Europe/Radio Liberty said they have asked their parent federal agency, the Board for International Broadcasting, to investigate the backgrounds of suspected collaborators named in the "60 Minutes" broadcast. If war crimes are proved, the employes will be fired, one official said.

The Immigration and Naturalization Service tried but failed to deport Radio Free Europe freelancer Vilis Hazner, "60 Minutes" reported. Hazner was suspended from the radio program during the investigation, but has since been rehired, according to New York bureau chief William Kratch.

"We're in a very difficult position," Kratch said. "We believe strongly in the presumption of innocence. Our own due process has found the man innocent. God forbid I'm the person who has to judge these people 40 years after the fact."