RJ Ellory, author of a number of successful novels, was caught red-handed by a fellow writer, Yahoo! reports.
Ellory, 47, took to Amazon to give his work overwhelming praise whilst panning the efforts of his rivals.
He described his own novel, A Quiet Belief In Angels, as a "modern-masterpiece" and gave all of his work 5-star reviews.
He was exposed on Twitter by spy novelist Jeremy Duns.
Duns said it took a "bit of searching and detective work" to uncover Ellory's actions after being tipped off by another author.
Ellory had been posting on the site under the alias Jelly Bean but it is suspected he may have also posted using other accounts.
The author, who won 'Crime Novel Of The Year' in 2010 for A Simple Act of Violence, has apologised for his actions.
"I wholeheartedly regret the lapse of judgment that allowed personal opinions to be disseminated in this way and I would like to apologise to my readers and the writing community," he said.
> 'Fifty Shades' new book contains 200 blank pages
> Blind author's novel saved by forensics team after pen runs out