An examination of Jeff Bezos' mobile revealed "an anomalous and extreme change in phone behavior" after the Amazon CEO received a file from a WhatsApp account associated with the Saudi crown prince, two UN special rapporteurs said on Wednesday.
There is a "reasonable belief" that the behavior on Bezos' phone was the result of Pegasus spyware sold to the Saudis by the Israeli NSO Group, the rapporteurs said in a statement summarising the findings of an "in-depth, forensic level examination."
Cybersecurity experts hired by Bezos, the world's richest man, concluded his phone was probably infiltrated by a video file sent from a WhatsApp account purportedly belonging to Prince Mohammed in 2018, according to a person familiar with the matter.
They said the device began leaking massive amounts of data about a month afterward, the source said.
Callamard, the special rapporteur for extra-judicial killings, and Kaye, special rapporteur for free expression, said the allegation of Saudi involvement "demands immediate investigation by the U.S. and other relevant authorities."
Saudi Foreign Minister Prince Faisal bin Farhan Al Saud dismissed the allegations on Wednesday.
"I think 'absurd' is exactly the right word," he told Reuters in an interview in Davos, Switzerland. "The idea that the crown prince would hack Jeff Bezos' phone is absolutely silly."
The allegations could nonetheless further damage relations between tech tycoon Bezos and Riyadh, and risk harming the kingdom's reputation with foreign powers and investors.
The alleged cyberattack is said to have taken place months before the 2018 murder of Saudi journalist Jamal Khashoggi, a fierce critic of the Saudi government and a columnist for the Bezos-owned Washington Post.
In October 2018, Citizen Lab reported on the use of NSO software to spy on the inner circle of Jamal Khashoggi just before his murder.
Citizen Lab's October report stated, with high confidence, that NSO's Pegasus had been placed on the iPhone of Saudi dissident Omar Abdulaziz, one of Khashoggi’s confidantes, months before.
Abdulaziz stated that the software revealed Khashoggi's "private criticisms of the Saudi royal family," which according to Abdulaziz "played a major role" in Khashoggi's death.
Prince Mohammed said last year that the killing was carried out by rogue operatives and that he did not order it.
In another previous flashpoint, Bezos' security chief said last year that the Saudi government had gained access to the Amazon CEO's phone and leaked messages to U.S. tabloid the National Enquirer between Bezos and Lauren Sanchez, a former TV anchor who the newspaper said he was dating.
A month before, Bezos had accused the newspaper's owner of trying to blackmail him with the threat of publishing "intimate photos" he allegedly sent to Sanchez.
The Saudi government has denied having anything to do with the National Enquirer reporting.
Saudi Arabia's U.S. embassy also dismissed the allegations.
"We call for an investigation on these claims so that we can have all the facts out," it said in a message posted on Twitter.
Amazon declined to comment.