Many of the prime suspects are dead, and most of the rest are older men who have not been in positions of influence for decades. But the great British spy hunt continues, adding new names each week to the list of confessed and suspected Soviet agents in Britain's security and diplomatic services during and after World War II.

The hunt began with the unmasking two years ago of the queen's art curator, the former Sir Anthony Blunt, as a Soviet spy, an accomplice of previously exposed traitors Anthony Burgess, Donald Maclean and H.A.R. (Kim) Philby, who had long ago fled to Moscow. Since then, the search for other spies has been pressed by the journalists of Fleet Street competing for new revelations and by shadowy but influential figures in the intelligence community here contending there is still a cover-up of worse treachery than has been revealed so far.

Besides the competitive pressures of British journalism and some tempting leaks from the deeply divided intelligence community, the enduring media fascination with spy stories is explained by the recent realization of the extent of Soviet penetration of the British government and intelligence services, the long government coverup of most of it, the tantalizing mystery that still shrouds these events and the traditional British love of detective and spy thrillers.

In recent weeks, two confessed wartime spies in British military intelligence have been exposed, suspicion has been cast on many more people alive and dead named in books and newspaper articles, and an argument has been revived inside the intelligence community over whether the late Sir Roger Hollis, head of Britain's MI5 internal security service from 1958 until 1966, was actually the most highly placed Soviet mole of all.

London's Sunday Times newspaper scored the latest coup by reporting that wartime British military intelligence officer and former Columbia Pictures executive Leo Long had confessed in the mid-1960s to being a spy recruited by Blunt. Long confirmed the report in a series of interviews after the Times' story was published, and said that he was interrogated about his activities but never prosecuted.

Now the newspaper is seeking to publish a story about allegations that a man with leftist ties in France a half century ago was connected to Blunt's "spy ring" while working as a magazine editor in the United States during and after World War II. In Washington, the man was identified as Louis Dolivet, a Frenchman born in Romania.

The subject of the story, who strongly denies the allegation, blocked its publication last Sunday by obtaining a court injunction in London against any Sunday Times story saying he was a spy or alleging that anyone thought he was spy. The part of the injunction covering allegations that he might have been a spy was lifted this week, allowing the Sunday Times to publish the story if it is cleared by the newspaper's libel lawyers, according to Sunday Times executive editor Don Berry.

Berry admitted that the subject of this story was a significantly "littler fish than some of the others," but contended that "every time a little bit sneaks out, it confirms that we still don't know the full story of those years."

"It's a wonderful sport, isn't it, chasing spies," he added. "Each big new revelation starts it all over again, and we join the chase. I think there is a lot more to be told, and we're going to continue pursuing it."

The Observer newspaper also joined the hunt with excerpts from a new book by spy-chasing free-lance journalist Nigel West that hinted at Long's recruitment as a spy by Blunt at Cambridge University. West also brought to public attention, after nearly 40 years, a former British Army officer named Ormond Uren, who was court-martialed during World War II and imprisoned for passing some information about his work in a sensitive military installation to the then national organizer of the Communist Party in Britain.

But West mistakenly described Uren as having been part of a group of students at Cambridge University who committed themselves to communism as the only means to prevent the takeover of Europe by fascism at the outset of the war. Burgess, Maclean, Philby, Blunt and Long all came from this group at Cambridge, centered on an exclusive debating society of mostly upper class, left-leaning intellectuals.

Uren, who was educated at Edinburgh University in Scotland, then added to the mountain of spy journalism in the media here with an article in the daily Times contending that if he had been among the privileged Cambridge set he "might now be in possession of immunity from prosecution like Blunt and Long or be drinking vodka and Georgian wine in a luxury KGB ghetto in Moscow," as Burgess, Philby and Maclean were able to do.

Journalists, government officials and members of Parliament here attribute much of the zeal of the continuing spy hunt to widespread resentment that many of the spies recruited from the Cambridge elite of the l930s have gone unpunished and to the mystery created by tight government secrecy shrouding each case until its disclosure in a book or newspaper article.

A book by former BBC producer Andrew Boyle led to Blunt's unmasking and a book by veteran British journalist Chapman Pincher made public the deep divisions within the intelligence community over whether Hollis, who died in 1973, was a Soviet agent when he ran MI5.

"If it had not been for Boyle's book, Blunt would still be working in Buckingham Palace," said Pincher, who also argued that his own revelations, criticized by Prime Minister Margaret Thatcher as not wholly accurate, may finally force a conclusive determination of whether Hollis "was the spy of the century."

Pincher said the Cambridge-recruited spies were "an extraordinary set who could have been running the country" if Burgess, Maclean and Philby had not been caught, mostly because the group's lifestyle, which included flamboyant homosexuality and alcoholism, made them careless. For this reason, he said, the case "will continue to fascinate" until and unless the government reveals everything known about it, including the names of other suspects that are still secret.

"We have this secrecy bug," said Pincher, "so instead it dribbles out, making it all look even worse. This is a cardinal error by the government."

But a well-informed British government source close to the intelligence services contended that Thatcher's unusually open approach to the Blunt case two years ago actually encouraged leaks of more information.

"She changed the ground rules when she responded to a limited amount of pressure from members of Parliament based on Boyle's book and took the lid off the Blunt thing," this source said. "She could have refused to answer.

"This broke the vow of silence about security that had applied even to prime ministers," the source said. "So others down the line figured there could be a bit more talking about past events in the security services."

Much of this talking has been done by former intelligence service officials to sympathetic members of Parliament and journalists specializing in spy-case investigations. The former officials argued that information about other suspects, particularly Hollis, showing the extent of the penetration of the British government and an alleged subsequent cover-up, would reveal much greater damage done to the country than is now believed.

These men are described by sources close to them as "some fairly distinguished people," including former members of high-level intelligence service committees who had investigated the suspected presence of a Soviet mole at or near the top of MI5 -- a probe so close to the plot of John LeCarre's spy thriller "Tinker, Tailor, Soldier, Spy" that many insiders believe it may have served as its model. Hollis, after his retirement as head of MI5 in l966, was repeatedly questioned during this investigation.

It reportedly cleared Hollis, but a number of the senior officials supervising the investigators still have strong suspicions he was a spy because of many unanswered questions about his behavior as MI5 chief, according to Pincher and government sources.