Richard Tomlinson: "I can do nothing but deny it"

Mr Tomlinson has also strongly denied Foreign Office claims that he was responsible for posting the 116 names.

"A denial might sound a bit thin, because I did threaten to put names on the Internet," he said in an interview with the BBC Six O'Clock News.

BBC Legal Affairs Correspondent Joshua Rozenberg: "The Foreign Office says that no-one else is in the frame"

"But I did not do it. If my former employers can find proof - well let them try.

"I know the finger points at me strongly, but I did not put the names on the site. I don't even know the address of the site they appeared on."

'No-one else in the frame'

Mr Tomlinson said he was quite happy for the authorities to see his computer, and he would offer them written permission to examine his Internet Service Provider's records.

"They can test it in a court if they want to use it as evidence," he said.

However, the Foreign Office insisted that the "balance of probabilities" pointed to Mr Tomlinson being responsible.

A spokesman said: "There is no-one else in the frame. Even if he did not physically put the names on the Internet, there's no real difference if he provided the names for someone else to do it."

The former spy has gone into hiding, and has received threatening e-mail. On Friday, the Sun newspaper published his e-mail address, calling him a traitor and urging readers to contact him.

Tomlinson: Living in Geneva

"I don't think I'm in danger from MI6, but I did wonder about some of the death threats I received by e-mail today," he said.

His family are concerned for his safety. His brother, Matthew, said on Friday that he could not contact him, but was convinced of his innocence and worried about what might happen.

Mr Tomlinson has been accused of posting the names on the Net because he held a grudge against MI6, after being dismissed by them and denied an industrial tribunal.

The BBC's Paul Reynolds: "The cat is well out of the bag"

After the list of agents became known to security forces on Wednesday, frantic efforts were made to remove it.

The site appeared to have closed down on Wednesday night.

But several "mirror" sites have now appeared on the Web. A search by BBC News Online found one such site in less than five minutes.

A Foreign Office spokesman said: "The information can be accessed. To an extent, the cat is out of the bag."

Officials are considering punitive action against the perpetrator of what has been called one of the biggest security breaches in recent years.

Police confirmed they were investigating the release of the names - said to include a Cambridge University academic and the son of a former Cabinet minister.

Embarrassment for MI6

Mr Tomlinson was sacked by MI6 in 1995 and jailed in December 1997 for breaking the country's Official Secrets Act.

He was released on probation after six months of his one-year sentence and has been pursued around the world since by UK Government injunctions.