Cybersecurity experts hired by Bezos, concluded his phone was probably infiltrated by a video file sent from a WhatsApp account purportedly belonging to Crown Prince Mohammed bin Salman 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.
However, Saudi Foreign Minister Prince Faisal bin Farhan Al Saud dismissed the charges.
"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 Bezos and Riyadh, and risk harming the kingdom's reputation with foreign powers and investors.