Saudi Crown Prince Mohammed bin Salman may have been involved in a plot to hack the phone of Amazon's billionaire boss Jeff Bezos, United Nations experts say.
UN special rapporteurs Agnes Callamard and David Kaye say they have information pointing to the "possible involvement" of the prince in the alleged 2018 cyberattack.
Saudi officials have dismissed the allegations as absurd.
Cybersecurity experts hired by Mr 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 afterwards, the source said.
Mr 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 US 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.
"The idea that the crown prince would hack Jeff Bezos' phone is absolutely silly."
The allegations could nonetheless further damage relations between tech tycoon Mr 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.
Prince Mohammed said last year the killing was carried out by rogue operatives and that he did not order it.
In another previous flashpoint, Mr Bezos' security chief said last year the Saudi government had gained access to the Amazon chief's phone and leaked messages to US tabloid the National Enquirer.
The messages were between Mr Bezos and Lauren Sanchez, a former TV anchor whom the newspaper said Mr Bezos was dating.
A month before, Mr Bezos had accused the newspaper's owner of trying to blackmail him with the threat of publishing "intimate photos" he allegedly sent to Ms Sanchez.
The Saudi government has denied having anything to do with the National Enquirer reporting.
Saudi Arabia's US embassy also dismissed the allegations.
Recent media reports that suggest the Kingdom is behind a hacking of Mr. Jeff Bezos' phone are absurd. We call for an investigation on these claims so that we can have all the facts out.
— Saudi Embassy (@SaudiEmbassyUSA) January 22, 2020
"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.