The National Enquirer's parent company attempted to blackmail Jeff Bezos by threatening to publish his intimate photographs, the Amazon chief executive has alleged.

Mr Bezos said the threat was meant to pressure him into dropping an investigation into how it obtained text messages sent to his mistress, which were published in the US tabloid last month.

On Thursday evening he published emails purporting to show an American Media Inc executive threatening to publish images of his genitals, as well as selfies showing him partly-dressed and separate images of his girlfriend Lauren Sanchez.

The email, apparently sent by AMI chief content officer Dylan Howard, described the images and added that the Washington Post, which Mr Bezos owns, was "poised to publish unsubstantiated rumors of The National Enquirer’s initial report".

Earlier this week the Post published a story quoting Mr Bezos' consultant Gavin de Becker, which suggested the publication was "politically motivated".

Mr Bezos has been repeatedly criticised by US president Donald Trump, who has also attacked the Post's coverage of his presidency.