Amnesty International Israel asked the Defense Ministry to revoke cyber firm NSO's defense export license two weeks ago, saying it had been proven that its software had been used in "a series of egregious human rights violations," after a Haaretz investigation revealed that the company offered Saudi Arabia a system for hacking cellphones.

"NSO has gone out of control," Amnesty Israel said.

Sources in the Defense Ministry agency that oversees defense exports said it was strict about granting licenses according to the law and that they could not discuss the existence of NSO's license for security reasons.

Amnesty Israel rejected the response and said it intended to pursue legal action.

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This summer, Amnesty International said one of its employees had been targeted by a hacker using NSO software.

The investigation published in Haaretz this weekend said NSO offered Riyadh a surveillance system mere months before Crown Prince Mohammed bin Salman began his purge of regime opponents.

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According to an article in Forbes magazine and reports from Citizen Lab, a Canadian academic think tank focusing on technology and human rights, among the surveillance targets were the satirist Ghanem Almasrir and human rights activist Yahya Asiri, who live in London, and Omar Abdulaziz, who lives in exile in Canada.