Historian Orlando Figes admitted today he was behind anonymous reviews savaging rival scholars' books which were posted on Amazon's website.
The finger of suspicion had been pointed in the direction of the Russian scholar's wife, law expert Stephanie Palmer, in a case which has drawn wide intrigue.
But in a dramatic twist to the literary whodunnit, Figes revealed he was fully responsible for the put-downs - and his wife had been trying to save him out of loyalty during a time of "intense stress".
He apologised to her, his lawyer and academics whose works were rubbished.
The professor, who has gone on sick leave from his job at London's Birkbeck College, admitted to being "stupid" - but said he had not intended to cause harm.
Comments posted online had slammed a work by academic Rachel Polonsky as "hard to follow" and one by Robert Service as "awful".
Meanwhile the reviewer "orlando-birkbeck" had praised a book by Figes as "fascinating".
Figes said in a statement: "I take full responsibility for posting anonymous reviews on Amazon.
"I have made some foolish errors and apologise wholeheartedly to all concerned.
"In particular, I am sorry for the distress I have caused to Rachel Polonsky and Robert Service.
"I also apologise to my lawyer to whom I gave incorrect information.
"I panicked when confronted with an email sent to academics and the press and instructed my lawyer without thinking this through rationally.
"This escalated the situation 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 for my health, and I owe her an unreserved apology."
Figes said he was "ashamed" of his behaviour and did not entirely understand why he acted as he did.
He said: "It was stupid - some of the reviews I now see were small-minded and ungenerous but they were not intended to harm.
"This crisis has exposed some health problems, though I offer that more as explanation than excuse.
"I need some time now to reflect on what I have done and the consequences of my actions with medical help."
A spokesman for Birkbeck College declined to comment on the issue, simply saying: "He is on sick leave and we are supporting him at this time."
A trace of a happy ending appears to have come out of the saga, in the form of a sales boost.
The Daily Mail's website reported Ms Polonsky saying of her book, Molotov's Magic Lantern: "It reached the top 500, then dropped to about 1,600 on Amazon's best-seller list. Now it is back to 500 again."Reuse content