The report said some of the interrogations took place after the war ended in 1975 and after Hanoi said all American prisoners had been returned. Some of the Americans may have been taken to the Soviet Union on regular supply flights from Vietnam, said the Soviet agents interviewed by "Australian 60 Minutes," which is modeled after the CBS News program. The Australian program was broadcast on Oct. 27, but its assertions were not publicized in the United States until The San Diego Union printed an article about the documentary last Sunday.
A spokesman for the Defense Department, Bob Hall, said this week that interviews with American prisoners who returned after the war had turned up no evidence of interrogation by Soviet agents. But Mr. Hall said the Pentagon was looking into the allegations.
Agents interviewed for the program said they believed that Americans who had been interrogated might have been killed after being returned to the Vietnamese. The United States, which withdrew its forces from Vietnam in 1973, lists 2,273 Americans as missing in Vietnam, Cambodia and Laos.
In the program, a former Soviet navigator identified as Pavel Ponomaryov said he had helped fly two Americans to the Soviet Union and that he had seen three other captured servicemen on flights from Vietnam.
Yuri Pankov, a Soviet reporter who took part in making the segment of the Australian program, titled "Missing in Action," has written an article on the same subject for the Soviet financial journal Kommersant. He wrote that at least one American had been taken to the town of Sary Shagan in the republic of Kazakhstan in the years immediately after the war. The State Department said on Friday that two diplomats from the American Embassy in Moscow had been sent to Kazakhstan about two weeks ago to investigate the report but had been forbidden to go to Sary Shagan, which is in a restricted area.
Oleg D. Kalugin, a former K.G.B. general brought back by President Mikhail S. Gorbachev to reorganize the intelligence agency after the unsuccessful coup in August, was among those interviewed for the program. Mr. Kalugin said he headed an interrogation team in Vietnam from 1975 to 1978 and questioned Americans there.
The Soviet agents said their goal in the interrogations was to learn about American equipment.