According to the paper, federal prosecutors are examining messages, including at least one photograph, first sent by the world’s richest man to news reporter Lauren Sanchez, with whom he was having an extramarital affair.

Last year, Mr Bezos hinted Saudi Arabia had played a role in the National Enquirer’s 11-page exposé of the affair.

The Wall Street Journal’s claims come days after experts working for Mr Bezos also concluded with “medium to high confidence” a WhatsApp account used by Saudi Crown Prince Mohammed bin Salman was “directly involved” in hacking the billionaire’s phone in May 2018, according to the FT, which saw the report.

The report was endorsed by two UN human rights officials.

Jeff Bezos' plan for future space colonies Show all 11 1 /11 Jeff Bezos' plan for future space colonies Jeff Bezos' plan for future space colonies An artist rendering of the future space colony that Jeff Bezos envisions as the future home of the human race Blue Origin Jeff Bezos' plan for future space colonies An artist rendering of the future space colony that Jeff Bezos envisions as the future home of the human race Blue Origin Jeff Bezos' plan for future space colonies An artist rendering of the future space colony that Jeff Bezos envisions as the future home of the human race Blue Origin Jeff Bezos' plan for future space colonies An artist rendering of the future space colony that Jeff Bezos envisions as the future home of the human race Blue Origin Jeff Bezos' plan for future space colonies An artist rendering of the future space colony that Jeff Bezos envisions as the future home of the human race Blue Origin Jeff Bezos' plan for future space colonies Jeff Bezos introducing a life-size model of the Blue Moon, a lunar lander that could move many tons of cargo between earth and the moon Blue Origin Jeff Bezos' plan for future space colonies An artist rendering of Blue Moon on the surface of the moon Blue Origin Jeff Bezos' plan for future space colonies Bezos also announced that his company Blue Origin will meet the current Administration's goal of putting Americans on the Moon by 2024 with the Blue Moon lunar lander Blue Origin Jeff Bezos' plan for future space colonies The Blue Moon would be powered by the BE-7 engine Jeff Bezos' plan for future space colonies Bezos also announced that his company Blue Origin will meet the current Administration's goal of putting Americans on the Moon by 2024 with the Blue Moon lunar lander Blue Origin Jeff Bezos' plan for future space colonies Bezos also announced that his company Blue Origin will meet the current Administration's goal of putting Americans on the Moon by 2024 with the Blue Moon lunar lander Blue Origin

The US attorney’s office has also been investigating whether Mr Bezos’s phone was hacked.

But according to The Wall Street Journal, who spoke to “people familiar with the matter”, evidence gathered by federal prosecutors includes a text message sent on 10 May 2018 from the phone of Ms Sanchez to her brother Michael Sanchez containing a “flirtatious message” originally sent from the Amazon boss.

The messages were reportedly among the materials handed to federal prosecutors as part of their investigation into whether American Media Inc – publisher of the National Enquirer – attempted to extort Mr Bezos, as he has claimed.

The materials given to prosecutors also include a message sent on 3 July 2018 from Ms Sanchez’s phone to her brother’s featuring a photo of a shirtless Mr Bezos.

Evidence of a payment of $200,000 (£152,000) from the National Enquirer to Mr Sanchez in October 2018 has also been given to prosecutors, and appears to support American Media’s earlier statements that Mr Sanchez was the source for the National Enquirer’s article on the affair.

Mr Sanchez has denied the allegations, telling The Sunday Telegraph that the images did not come from him and that he “sincerely believes” they were obtained illegally.

The report into alleged Saudi hacking of Mr Bezos’s phone details how his iPhone X apparently started surreptitiously sending vast amounts of data immediately after he was sent an encrypted video file from the Saudi Crown Prince’s WhatsApp account in May 2018.

The pair had exchanged numbers weeks beforehand during a dinner they both attended in Los Angeles.

Prince Mohammed had been on a trade mission in an effort to attract further investment by US executives in Saudi Arabia.

But the relationship between Mr Bezos and Prince Mohammed deteriorated after the murder of Washington Post journalist Jamal Khashoggi at the Saudi Consulate in Istanbul. A CIA investigation concluded the Saudi Crown Prince personally ordered the assassination of the writer, who had written articles critical of the Saudi government.

The Saudi embassy has described the allegations they hacked Mr Bezos’s phone as “absurd”.

In a statement to the FT after the publication of the report carried out on behalf of Mr Bezos, a Saudi official said: “Saudi Arabia does not conduct illicit activities of this nature, nor does it condone them.