Labour MP Geoffrey Robinson has denied claims that he was a Cold War spy who passed confidential government files to communist Czechoslovakia in the 1960s.
The Mail on Sunday says the allegations are contained in files archived by the current Czech government.
They centre on information about Britain’s nuclear deterrent, including its Polaris missile programme, and details about Nato.
Mr Robinson said the allegations against him were untrue.
A statement issued via his lawyers said: “At no time did he ever pass confidential government documents or information to any foreign agent and he did not have access to such material.
“The allegations made by the Czech authorities 50 years ago are a lie.”
The Mail on Sunday says the claims are contained in 390 pages of files compiled by the StB security service in Cold War Czechoslovakia and now administered by the Czech Republic’s state security archives.
The files allege scores of meetings with a Czech “handler” between 1966 and 1969.
Last year in a separate development, the Labour Party denied claims that Jeremy Corbyn had either been a collaborator or an agent of the communist regime in Czechoslovakia in the 1980s.
The party said the claims had come from a single source and were “absurd and hallucinogenic”.
Mr Robinson has been the MP for Coventry North West since 1976, and was paymaster general in 1997-1998 when Tony Blair was prime minister. He is also ex-chairman of Jaguar and Coventry City FC.
Communist rule lasted in Czechoslovakia from 1948 until the “Velvet Revolution” in 1989.
Less than four years later, the “Velvet Divorce” saw the country divide into the Czech Republic and Slovakia.