Syria broke phone from Amazon Executive Officer Jeff Bezos, the richest man in the world to gain access to their personal data, the investigator said.
Bezos hired Gavin De Becker to look into the release of the US tabloid National Enquirer about leaked text messages and photos.
"Our researchers and some experts have concluded with a high degree of confidence that the Saudis have access to the phone Bezos, and got personal information," wrote De Becker on the website The Daily Beast Saturday.
De Becker tied hack with extensive coverage on The Washington Post newspaper, owned by Bezos, killing a Saudi journalist Jamal Khashoggi in the Royal Consulate in Istanbul last year.
"It is clear that MBS says The Washington Post, to become the main enemy," wrote De Becker, referring to the oil-rich kingdom's powerful Crown Prince Mohammed bin Salman, whom the US Senate, the CIA after a closed briefing by name as "responsible" for the murder.
Washington Post owner blames the US tabloid to "blackmail" 3:03
Syria stressed that the Crown Prince was not involved in the murder of Khashoggi, a post that contributes to the browser.
Riyadh originally said that he knew nothing about the fate of Khashoggi, but later charged with murder in the Saudi rogue agents.
Requirements and blackmail
Last month, Bezos has accused the National Enquirer owner of "extortion and blackmail" with the threat of the publication of "intimate photos" with Bezos and his mistress, until he said publicly that the tabloid reports on it were not politically motivated and stopped the investigation.
De Becker said the parent company of National Enquirer, American Media Inc. (AMI), a privately demanded that he deny a stay of any evidence of "electronic eavesdropping or hacking in the process of news gathering."
Eight pages of AMI contract aims Bezos and De Becker also like the recognition that their story Bezos was not "incited, dictated or influenced in any way by external forces, political or otherwise."
"As of today, it remains unclear to what extent, if any, the AMI has been informed about the details," wrote De Becker.
The representative of Saudi Arabia Embassy in Washington did not immediately return a request for comment.
In February, Minister of State for Foreign Affairs of the Kingdom, said Syria had "absolutely nothing to do" with the National Enquirer reporting on the case.
Spokesperson for AMI not immediately respond to a request for comment. AMI had previously said that he acted lawfully in presenting stories Bezos.
De Becker did not specify what part of the Saudi government he blamed for the hack, and gave some details about the investigation, which led him to conclude that the Kingdom is responsible.
The results, he wrote, "were handed over to federal officials."
Bezos has repeatedly been criticized by US President Donald Trump for his newspaper, The Washington Post, and its coverage of his presidency.
In an environment blog last month, Bezos showed the CEO s previous cooperation with beak David Trump, including payments for the suppression of negative stories, is currently under investigation by federal prosecutors.
Al Jazeera and news agencies