WASHINGTON — Despite misgivings in Moscow, Pentagon investigators are intensifying their search for Cold War-era Russian records that could confirm reports that American servicemen from World War II and the Korean War were held and died in the network of labor camps known as the gulag.

The Russian government is cooperating with the effort, but it has been deeply skeptical of the evidence available so far — mainly eyewitness accounts with limited details and little or no documentation.

The Russians have questioned the authenticity and validity of one of the Pentagon's most compelling sources, a Russian emigre who claims he learned while in internal exile in the former Soviet Union that dozens of American servicemen — some identified by name — were imprisoned in the 1950s.

The Defense Department released to The Associated Press this week a compilation of reports from dozens of sources who claimed to have seen American military personnel in such notorious prisons as Lubyanka in Moscow and such obscure labor camps as Bulun in the remote northern reaches of Siberia.

The reports, which collectively are known within the Pentagon as the "Gulag Study," include brief summaries of what eyewitnesses — in most cases not identified by name — say they saw in the labor camps. More than two dozen reports relate to camps around Vorkuta, a Siberian city above the Arctic Circle.

Some examples:

—A person described as a Polish witness said an American prisoner arrived at Vorkuta's coal mine No. 6 in about June 1953. Other prisoners told the witness that the American was the pilot of a spy plane shot down by the Soviets. The witness said the American appeared to be about 40 years old and more than six feet tall, and that he saw him while the witness and other Polish prisoners were being prepared for release.

—John H. Noble, an American who was interned by the Germans during World War II and later taken by the Soviets to a Vorkuta labor camp, said he was told by a Yugoslav national at camp No. 3 that eight survivors from a U.S. Navy spy plane downed by the Soviets over the Baltic Sea in 1950 were being held in the Vorkuta area. The Soviets released Noble to U.S. authorities in 1955. (A Navy Privateer reconnaissance plane carrying a crew of 10 was shot down by Soviet fighters over the Baltic on April 8, 1950. The entire crew is unaccounted for. The Pentagon is investigating the case.)

—Reports from three separate sources referred to sightings in the 1950s of what appears to be the same American GI in camps at Bulun, a port on the Lena River in northern Siberia. One reported him as Dick Rozbicki, a soldier captured during the Korean War; another reported him as Fred Rosbiki, a commando; the third report, received second-hand from a Catholic priest in 1958, referred to a Lt. Stanley Rosbicki.

—A Soviet veteran claimed in 1996 to have seen a U.S. prisoner of war in May or June 1953 in Moscow. The American was said to have been an Air Force F-86 fighter pilot who was forced to land in North Korea, captured and taken to Moscow and made an instructor at the Monino Air Force Academy from 1953-58. Also, a Polish witness reported sharing a cell at the Lubyanka prison in Moscow in 1948 with a U.S. Army sergeant whom he had seen a year earlier at a prison in Potsdam, Germany.

The Pentagon has been pressing the Russians for several years to pursue clues that American servicemen were imprisoned in Siberia during the Cold War.

And now the case has been bolstered by more specific information.

In a note accompanying the "Gulag Study," Robert L. Jones, the deputy assistant secretary of defense for POW and MIA affairs, cautioned against assuming the study is accurate in every detail. The material was provided to the Russian government in April 2000 but not released publicly until now.

The U.S.-Russian Joint Commission on POW/MIAs, created in 1992 to investigate the fate of American servicemen missing from World War II and the Cold War period, intends to arrange visits to some of the former Soviet labor camps mentioned in the report, Jones wrote.

Norman Kass, a senior official on the U.S. side of the commission, traveled to Vorkuta last October to arrange for a private Russian group to search for records from the former labor camps there.

One such camp is of particular interest to the Pentagon: the Kirovskij mining camp near the Kamenka River in the sub-Arctic pine forests of the Krasnoyarsk region in Siberia. A Russian emigre — whose identity has not been released, even to the Russians — who had been in internal exile in Siberia in the 1950s told Pentagon investigators last year that he learned of 22 Americans held in there in 1951.

Russian officials have questioned the credibility of the assertions.

Comment on this story

The 22 names were provided by a woman who the emigre said worked in the Kirovskij camp in 1951-52. He said the woman had the men write their names on scraps of newspaper, then put the paper in a jar and buried it.

One of the 22 names correlates with a U.S. soldier listed as unaccounted for from the Korean War. He is Chan Jay Park Kim, a Hawaiian of Korean descent who was captured early in the war. In captivity in Korea he was known to have used a pseudonym, George Leon, to mask his ethnic background. It is that name which appears on the list of 22 Americans.

Also on the list of 22 is the surname Hatch. An Army Sgt. 1st Class Robert Hatch of Aiken, S.C., is missing in action from the Korean War. Another, listed as Hubert Johnson, could be Army Cpl. Herbert Johnson of McLennan, Texas, who was declared missing in action Nov. 27, 1950 in Korea.

On the Net: Defense Prisoner of War/Missing Personnel Office: www.dtic.mil/dpmo