Amazon forces people to buy James Comey book if they want to review it

The ex-FBI director's book isn't the first to have proven too controversial to review

Former FBI Director James Comey poses for photographs as he arrives to speak about his new book "A Higher Loyalty: Truth, Lies, and Leadership" in New York (Getty Images)

Amazon is banning people from reviewing James Comey's book until they buy it.

The company will only let people who buy the explosive new book through its own channels write about it on the website.

The decision has apparently been made to stop supporters of Donald Trump – who is heavily attacked in the book – pushing down its ranking without actually reading it. Similar campaigns were waged on books like Michael Wolff's Fire and Fury and Hillary Clinton's account of the election, both of which saw Amazon remove one-star reviews.

If people try and review the ex-FBI director's book without buying it, they will see an error message informing them that there are "limitations on submitting reviews".

The site's community guidelines allow it to limit people who can review when there is "unusually high numbers of reviews for a product posted in a short period of time".

The book currently has a firm five star rating, with 89 per cent of people giving it full marks. Only two per cent of reviewers scored it with one star.

It is also the site's best-selling book in the US, having spent five weeks on the list.

Usually, Amazon will let anyone review any item, even if they have bought it from somewhere else, though they are restricted to five such reviews per week. If they have bought it from Amazon, and use the same account to write the review, then they will get a little badge making clear that they are a verified purchaser.

Mr Comey will speak at Amazon this week, in what is thought to be part of a leadership seminar.