German spy infiltrates key British institute

"Eckart" would have come into contact with Britain’s then Prime Minister, Margaret Thatcher, as well as other key politicians during his time at the RIIA, the Times said.

He supplied information on NATO planning as well as British Navy manoeuvres and handed over a number of documents apparently stolen from the RIIA, it said.

The Times said that Britain’s Home Secretary Jack Straw had told Members of Parliament that more than 100 people had been investigated as part of inquiries to establish the true identity of "Eckart", but as yet no-one faces prosecution.

A spokeswoman for the Home Office declined to comment specifically on the Times report.

"We do not comment on intelligence investigations, nor matters for the police or prosecuting authorities," she said. "The government is satisfied with arrangements for bringing the results of such investigations to the attention of the prosecuting authorities.

"As the Home Secretary has explained in parliament, there is a clear distinction between unsubstantiated information found in the files of former communist regimes and evidence that can be brought before a court.

"In this country there is a long tradition that people are innocent until convicted in a court of law," she said.

The Times said the RIIA, often referred to as Chatham House in reference to its central London headquarters, had launched an inquiry to try and find out the true identity of the spy.

It said staff at the institute were surprised and dismayed to hear that one of their colleagues during the 1980s had been a Stasi spy.