Mystery surrounds the authorship of the site. The maverick former spy Richard Tomlinson denied last night that he posted the list. "It's not me. I don't know who has done this," he said.
The Foreign Office immediately issued a notice requesting the media not to identify the location or content of the website, saying "such action could put lives at risk". Government lawyers are talking urgently to the US-based company which hosts the website, seeking to have it shut down on the grounds that it breaks the law as it contains information which breaches the Official Secrets Act.
The site is reported to contain "a large number" of names, and the alacrity with which the Government reacted after discovering its presence yesterday suggests that some or all of the content is accurate.
Rear Admiral David Pulvertaft, of the Defence Advisory Notice Secretariat, said publication of the agents' names could "be gravely damaging" and "put lives at risk". And he added: "Officials here hope they will have this website removed as speedily as possible." He said he had no information on who had produced the site and said there was nothing to suggest it had been produced by Mr Tomlinson.
Twice in the last fortnight Mr Tomlinson, 35, has crossed swords with the Government over the global network. Since 30 April, two websites he created have been closed down. The first was hosted by a Swiss-based Internet company, and the second last Thursday by an American provider, Geocities.
The Treasury Solicitor, Anthony Hammond, acting on behalf of the Attorney- General, obtained an injunction in Geneva on 30 April preventing Mr Tomlinson from disclosing information on the Internet or by other means. Mr Tomlinson had then moved the pages to a California-based site whereupon the Treasury Solicitor wrote to the site provider drawing its attention to the Swiss injunction saying Mr Tomlinson would be in breach of his civil obligations to the Crown if he went ahead with publication of this material.
But Mr Tomlinson said the site was now back up and running. Although he has threatened to identify serving MI6 officers, he insists he has not yet done so.
Mr Tomlinson was sacked by MI6, the counter-intelligence agency, in 1995 and jailed in 1997 for breaking the Official Secrets Act by showing a book synopsis on his career to a publisher. After his release he left the UK, eventually settling in Geneva, from where he has launched a crusade against what he considers to be MI6's gross inadequacies and illegal activities.
John Wadham, director of human rights organisation Liberty and Mr Tomlinson's solicitor, said last night: "He was sacked by MI6, he thinks unfairly, and was banned from going to the industrial tribunal.
"Since then, he feels he has been harassed by the authorities. He has had injunctions against him in every country he has visited, been ejected from Australia, the US and France, and has not been able to obtain a visa to settle anywhere to build a new life."
Although the Government has asked the media not to interpret the information in the website as being "widely disclosed", it is likely that its content will already have been indexed and effectively stored.
Even if the page is subsequently removed, the detail will remain in the search engines - so that a name which appeared on the page will still be flagged if someone used the correct combination of words to find it.
The US media will probably have no qualms about posting the site's location as the First Amendment defends the freedom of the press. Anti-censorship advocates who hear of Mr Tomlinson's case are also likely to create copies, or "mirrors", of his site, leading to a situation where the Government has to try to shut down an ever-expanding number of sites all over the world. The site's existence puts a premium on rapid action by the British government.Reuse content