Israeli spyware firm NSO Group’s US lobbying campaign just got a lot more complicated after UN investigators today concluded that Saudi use of its Pegasus spyware was the “most likely explanation” for a 2018 hacking attack against Amazon CEO and Washington Post owner Jeff Bezos.

UN human rights experts Agnes Callamard and David Kaye called for an “immediate investigation by US and other relevant authorities” into Saudi Arabia’s alleged surveillance in a press statement. They said the allegations underscore the “pressing need for a moratorium on the global sale and transfer of private surveillance technology.”

The comments come after a forensic analysis of Bezos’ phone concluded with a “medium to high confidence” that he was hacked after receiving a video from Saudi Crown Prince Mohammed bin Salman’s WhatsApp account. Riyadh has been sharply critical of The Washington Post’s coverage of the kingdom, including columns by murdered dissident Jamal Khashoggi.

“The information we have received suggests the possible involvement of the Crown Prince in surveillance of Mr. Bezos, in an effort to influence, if not silence, The Washington Post’s reporting on Saudi Arabia,” Callamard and Kaye wrote. The Saudi Embassy in Washington has denounced the accusations as “absurd.”