MOSCOW (AP) _ The KGB has admitted that its forerunner framed and imprisoned a Hasidic Jewish leader in 1939, leading to his death in a labor camp, the official Tass news agency reported Friday.

Representatives of the Lubavitch Hasidic movement welcomed the disclosure but said they still were seeking the return of 12,000 religious books seized following the 1917 Revolution.

''They're our books, and we're determined to get them back,'' said Rabbi Yosef Aharonov of Jerusalem.

Tass said the Ukrainian branch of the security police handed over documents this week to the Lubavitch movement about the persecution of Rebbe Levi Y. Schneerson, who led the movement until his death in 1944.

His son, Menachem M. Schneerson of Brooklyn, N.Y., is the current rebbe, or spiritual leader, of more than 1 million Lubavitch Hasidim in the United States, Israel and other countries.

Aharonov, who heads the Lubavitch movement in Israel, said in an interview in Moscow on Friday that the documents came from the archives of the NKVD, the KGB's precursor during the Stalin era.

''They prove that the rebbe was subjected to 10 months of vicious interrogation, including night interrogations, and then framed for 'anti- Soviet propaganda,''' Aharonov said.

The Tass report said the rebbe had been ''rehabilitated,'' or posthumously vindicated by the government. The documents, including minutes of the interrogation, show that Schneerson was ''framed up and executed by Stalin's secret police,'' the state news agency said.

Aharonov said the rebbe died of ill-treatment in a camp in Soviet Kazakhstan.

The Lubavitch movement takes its name from the town in Byelorussia where it was founded two centuries ago. Its members strictly observe the Sabbath, Kosher dietary laws and other traditional Jewish practices. Most of the adult men wear black hats and clothes.

Leadership of the movement has been handed down through the Schneerson family for seven generations. The movement estimates that it has a few hundred followers in the Soviet Union, out of the country's 2.8 million Jews.

Aharonov and three other senior Lubavitch rabbis have been in the Soviet Union for several months working for release of the 12,000 books, part of the personal library of Sholom Ber Schneerson, father of the persecuted leader and grandfather of the current rebbe.

He put the mostly Hebrew texts in a private warehouse in Moscow for safekeeping as the German army advanced on the town of Lubavitch in 1916. In the early 1920s, the Soviet government transferred the books to the Lenin Library.

Konstantin Mezhlumian, a spokesman for the Soviet Ministry of Culture, said in a telephone interview that the collection was nationalized after the Bolshevik Revolution and is in good condition.

Aharonov said Soviet officials denied for years that the books existed, refused to allow Hasidim to see them and have not proven they were legally nationalized.

''They only dreamed up this nationalization thing'' after a Lubavitch librarian identified some of the volumes in the Lenin Library last fall, he said. ''We have had eminent Soviet lawyers review all the documents, and they say the books are still ours, legally as well as morally.''

Aharonov added that President Bush raised the issue of the books with Soviet President Mikhail S. Gorbachev during their summit meeting last month. A senior aide to Gorbachev told the Lubavitch movement that an order to return the books to the Schneerson family is awaiting Gorbachev's signature.