Poland’s story hospital says that newly seized papers advise former boss and Solidarity favourite Lech Walesa was an informer.
The papers were taken progressing this week from a home of a former communist-era interior minister, Gen Czeslaw Kiszczak.
Lukasz Kaminski, conduct of a Institute of National Remembrance, pronounced a papers seem authentic.
Mr Walesa has prolonged denied being an informer in a 1970s.
The former boss pronounced a new materials could not issue from him, according to Polish radio.
The 279 pages of papers have not nonetheless been scrupulously analysed, and will be done open in due course, Mr Kaminski said.
Gen Kiszczak’s widow had wanted to sell a documents, a hospital said.
The state physique prosecutes communist-era crimes.
Analysis: Adam Easton, BBC News, Warsaw
The claim that Lech Walesa upheld on information in a early 1970s to a comrade tip police, before he became a favourite of a Solidarity trade union, is not new.
Mr Walesa, who was privileged of a assign by a justice in 2000, says a communists falsified papers about him to try to harm his reputation.
It is doubtful these records will change many Poles’ minds about Mr Walesa since a claim is common believe and he is still widely dignified for his purpose in bringing down communism in 1989.
Mr Kaminski gave sum of what he claimed was inside a record on Mr Walesa, covering a duration 1970-6:
“Inside a personal record there is an pouch and inside, a palm created joining to concur with a tip military sealed ‘Lech Walesa – Bolek’,” he said.
Mr Kaminski pronounced that among a papers in this folder were some “hand-written confirmations of receiving funds”, sealed with a pseudonym ‘Bolek’.
“In a work folder… are many reports by a tip adviser with a pseudonym ‘Bolek’ and records by tip military officers from meetings with a tip informant,” a executive added.
Mr Walesa heartily denied long-standing allegations of partnership in a BBC talk in 2008.
“Nothing like that happened. we had no change over what a tip military did and wrote,” he said. “You will not find any signature of cave similar to combine anywhere,” he went on.
Timeline: Lech Walesa
1943: Born in Popowo, Poland. Later trains as an electrician and starts operative during a shipyards in Gdansk
1980: Becomes personality of Solidarity
1981: Arrested in anti-democracy crackdown
1982: Released, Polish martial law eased
1983: Awarded Nobel assent prize for his purpose in Solidarity – a initial giveaway trade kinship in a Soviet bloc
1988: Leads a array of national strikes
1990: Elected boss of Poland
1995: Defeated in presidential election
2000: Defeated again in presidential poll; privileged of confidence use partnership by a special court