A veteran security consultant who works for Amazon Founder and CEO Jeff Bezos has accused Saudi Arabia of hacking into Bezos' smartphone and alleging sharing personal information about his extra-marital affair to a media outlet.

The monarchy was "intent on harming Jeff Bezos" over The Washington Post (owned by Bezos) coverage of murdered journalist Jamal Khashoggi, wrote Gavin de Becker in a first-person account published in The Daily Beast on Saturday.

"Our investigators and several experts concluded with high confidence that the Saudis had access to Bezos' phone, and gained private information," de Becker said.

The private phone messages of Bezos sent to his lover, former TV anchor Lauren Sanchez, were published in The National Enquirer in October.

"As of today, it is unclear to what degree, if any, AMI (the parent company of The National Enquirer) was aware of the details,a added de Becker.

The inquiry by de Becker included a broad array of resources including extensive discussions with top Middle East experts, Saudi whistleblowers, people who personally know the Saudi Crown Prince Mohammad bin Salman (also known as MBS), people who work with his close associate Saud al-Qahtani, among others.

Saudi journalist Khashoggi was murdered at the Saudi embassy in Turkey in October 2018.

"Some Americans will be surprised to learn that the Saudi government has been very intent on harming Jeff Bezos since last October, when the Post began its relentless coverage of Khashoggi's murder," wrote de Becker.

Saudi Arabia has denied involvement in the Bezos affair.

"In October, the Saudi government unleashed its cyber army on Bezos (and later me). Their multi-pronged campaign included public calls for boycotts against Amazon.com and its Saudi subsidiary, Souq.com,a claimed the Bezos security chief.

In a post on blogging platform Medium in February, Bezos accused the publisher of National Enquirer of "blackmail" and "extortion".

"Rather than capitulate to extortion and blackmail, I've decided to publish exactly what they sent me, despite the personal cost and embarrassment they threaten," Bezos wrote in the post while saying that the "top people" at the National Enquirer were responsible for the extortion and blackmail.

Referring to AMI's Chairman and CEO, David Pecker, Bezos titled his post "No thank you, Mr Pecker" and alleged that AMI threatened to release compromising photos of him.

"I was made an offer I couldn't refuse," wrote Bezos. "Or at least that's what the top people at the National Enquirer thought. I'm glad they thought that, because it emboldened them to put it all in writing."

Bezos and his wife, MacKenzie Bezos, are getting divorced after 25 years of marriage.