The future of one of Britain's leading historians was looking increasingly uncertain tonight after he admitted that he was the author of anonymous reviews that praised his own work as "fascinating" and "uplifting" while rubbishing that of his rivals.

In a row that has scandalised the academic world Orlando Figes, one of the stars of contemporary history, had issued a string of legal threats to academic colleagues, literary journals and newspapers that suggested he might have written the reviews posted on Amazon.co.uk.

When challenged about the reviews, Figes's lawyer initially denied Figes was the author and threatened legal action. In a later statement, Figes blamed them on his wife, the barrister Stephanie Palmer.

But today Figes, a professor of history at Birkbeck, University of London, admitted "full responsibility" for the posts, saying he had been under "intense pressure". He added: "I have made some foolish errors and apologise wholeheartedly to all concerned."

Rival historian Robert Service, whose work on the history of communism Figes described as "awful" in the Amazon posts, said he and his wife had been through hell. "I am pleased and mightily relieved that this contaminant slime has been exposed to the light and begun to be scrubbed clean," said Service, who is professor of Russian history at St Antony's College Oxford. "I have been made acutely aware that a solitary malpractitioner, if he has an abundance of money and malice, can intimidate all and sundry – and that includes both scholars and journalists."

John Sutherland, professor of English at University College London, suggested Figes's position at Birkbeck could be under threat. "On the whole academics are pretty tolerant," he said. "Clearly in the present climate he's a star, and Birkbeck needs stars because of the upcoming research assessment exercise. They'll find it easy to prove that he provides impact. On the other hand, he's done something that's dishonest and possibly actionable."

The row began two weeks ago when historians noticed reviews on Amazon praiseing Figes's books and attacked those of academic rivals. Comments under the alias "orlando-birkbeck" and "Historian" called Rachel Polonsky's book Molotov's Magic Lantern "hard to follow" and Service's Comrades "awful", while praising Figes's study of Soviet family life, The Whisperers, as "a fascinating book … [that] leaves the reader awed, humbled, yet uplifted".

Service raised the matter of the rogue reviews with other historians and contacted Figes, who first suggested the two could "mend their relations" before his lawyer, David Price, issued a legal warning.

The next day Figes turned his fire on the TLS after its diary quoted some of the comments from its website, which suggested "that Orlando Figes and orlando-birkbeck are one and the same" and calling on Figes to clear up the matter.

Price contacted the newspaper, denying that Figes had any involvement in the reviews, demanding a "corrective publication", and suggesting that his client would be entitled to damages.

Just a few hours later Price issued a new statement, this time saying that Figes's wife had posted the comments, and that Figes himself had "only just found out about this, this evening".

But after a week of questions and increasingly critical headlines, Figes today revealed that he had been responsible for the comments.

He apologised to Polonsky, Service and his lawyer – "to whom I gave incorrect information" – for actions he called "stupid", adding: "Some of the reviews were small-minded and ungenerous, but they were not intended to harm."

He described a state of panic when he first saw the email sent by Service, which made him instruct his lawyer "without thinking this through rationally.

"This escalated the situation," he said, "and brought more pressure on myself by prompting a legal response. My wife loyally tried to save me and protect our family at a moment of intense stress when she was worried about my health. I owe her an unreserved apology."

Service said the episode underlined the need to rethink libel law. "I hope everyone can see the urgent need to do something about the laws of libel and to decontaminate the ground of public debate."

As the historians were left licking their wounds the editor of the TLS, Peter Stothard, said the issue of poisonous online reviews needed to be kept in proportion. "There's nothing new about oversensitive writers, and nothing new about anonymous criticism, both of which have existed since time immemorial. What is new and is regrettable is when historians use the law to stifle debate and to put something in the paper which is untrue."

He added that it was "quite different" for a footballer or singer to panic and call in the lawyers. As a specialist in Russian history, Figes's "whole business is replacing a mountain of lies with a few truths".

Figes was unavailable for further comment today and a spokesman from Birkbeck added: "He's on sick leave and we're offering our support."

Clues on the web

'Makes you wonder why it was published'

Description by "Historian" of Molotov's Magic Lantern, by Rachel Polonsky:

"This is the sort of book that makes you wonder why it was ever published … Her writing is so dense and pretentious, itself so tangled in literary allusions, that it is hard to follow or enjoy."

"Historian" described Robert Service's 2008 work Comrades, a world history of communism, as 'rubbish':

"This is an awful book. It is very poorly written and dull to read … it has no insights to make it worth the bother of ploughing through its dreadful prose."

The same reviewer found one writer's work rather more to their liking. Orlando Figes's 2008 The Whisperers was "beautiful and necessary":

"A fascinating book about the interior lives of ordinary Russians … it tells us more about the Soviet system than any other book I know. Beautifully written, it is a rich and deeply moving history, which leaves the reader awed, humbled, yet uplifted … Figes visits their ordeals with enormous compassion, and he brings their history to life with his superb story-telling skills. I hope he writes for ever."