The BBC's Political Correspondent Nicholas Jones reports on two more left-wing academics who deny the allegations

Vic Allen, 77, a former leading member of the Campaign for Nuclear Disarmament (CND), said he had "no regrets" over providing information to the East German Stasi secret police.

The retired Leeds University professor, from Keighley, North Yorkshire, said he did pass on information about CND's activities. But he said he considered that perfectly legitimate because he belonged to a pro-Soviet, pro-East German faction of the group.

He told BBC Two's The Spying Game: "I have no shame. I feel no regrets about that at all.

"My only regret is that we didn't succeed."

He and the former editor of the left-wing newspaper Tribune Dick Clements, were in regular contact with the East German secret police, the Stasi, according to the security service's files.

The allegations come only 24 hours after the BBC unmasked Hull University lecturer Robin Pearson as a former Stasi agent.

Earlier in the week, it was revealed that Melita Norwood, an 87-year-old great-grandmother, and former Scotland Yard detective John Symonds had also betrayed Britain during the Cold War.

The latest revelations suggest the KGB and the Stasi saw Mr Allen and Mr Clements as "agents of influence", who could provide useful information and help promote pro-Soviet policies.

John Symonds was a "Romeo agent"

Mr Clements, who edited Tribune in the 1960s and 1970s and later became an adviser to Labour leader Neil Kinnock, said he met Soviet officials but was never controlled by them.

He said he never compromised Tribune's editorial integrity and considered any intelligence reports sent back to Moscow must have been highly exaggerated. The Sunday Times says he was given the codename Agent Dan.

The BBC's Nick Jones: "Many more names could come forward this week"

The BBC's Political Correspondent Nick Jones said: "There were a lot of people on the left in British politics who were regularly chatted to by officials at the Soviet embassy in London."

Mr Jones, a former industrial correspondent, said he himself had spoken to Soviet labour attachés at the Trades Union Congress conference.

"There was no doubt they were very active in collecting information, although much of it was in the public domain," he said.

Mr Jones said many more names could come out of the files and prosecutions were unlikely.

Lecturer accused

At least one other academic is identified in The Independent on Sunday as a Stasi agent.

Robin Pearson still has not commented on the allegations

It says Dr Gwyneth Edwards, a modern languages lecturer at Loughborough University, reported back to her controllers on any anti-communist comments made by visiting German academics.

The Sunday Times says a student from Leeds, Fiona Houlding, was also recruited by the Stasi and given the codename Diana.

Ms Houlding, now 36, reportedly fell in love with an East German while studying in Leipzig in the 1980s and gave information to the authorities.

The paper says at least four other Stasi agents in Britain are likely to be named later this week.

'No influence'

A Home Office spokeswoman said: "We have been briefed on these Stasi cases but we are not commenting on the detail of further cases."

Former national chair of CND Joan Ruddock, now Labour MP for Lewisham, denied claims that Mr Allen might have "swung" the organisation towards Moscow.

She said: "CND was an open, democratic organisation and our opposition to Soviet weapons meant we would never have gone in that direction."

Ms Ruddock defeated Mr Allen in a battle for the CND leadership in 1985.

But she said: "He certainly had no influence on national CND, and as a pro-Soviet could never have succeeded to the chair.

"CND was as opposed to Soviet nuclear weapons as Western ones."