Montreal-based Saudi activist Omar Abdulaziz launched a lawsuit on Sunday against Israeli cyber company NSO, claiming that the company's software was used to hack his cellphone in order to track conversations with murdered Saudi journalist Jamal Khashoggi.

As revealed in Haaretz last month, the cyber firm sells its software to oppressive regimes, which is used to track dissidents.

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"The hacking of my phone played a major role in what happened to Jamal, I am really sorry to say," Abdulaziz told CNN. "The guilt is killing me."

The lawsuit filed by Abudlaziz's lawyers in Tel Aviv alleges that the cybersecurity firm breached international law by selling this technology to oppressive regimes, knowing that it could be used to violate human rights.

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This lawsuit comes on the heels of others that were filed against the Israeli firm in Israel and in Cyprus by citizens of Mexico and Qatar.

"NSO should be held accountable in order to protect the lives of political dissidents, journalists and human rights activists," the Jerusalem-based lawyer Alaa Mahajna, who represents Abdulaziz, told CNN.

Abdulaziz first spoke publically about his correspondence with Khashoggi after researchers at the University of Toronto's Citizen Lab found that his phone had been hacked by military-grade spyware – adding that the software was created by the Israeli firm and deployed by the Saudi government.

NSO responded to the accusations, calling the lawsuit "baseless" and saying that the lawsuit contains "no evidence that the company's technology was used. Furthermore, it contains details that are not based in reality."

NSO added, "NSO is a technology company that is uninvolved with how our products are used once they are sold to our customers. This is a lawsuit based on sensationalist journalism that is unbound to reality in order to create headlines."

Open gallery view Screen grab: Saudi activist who received asylum in Canada, Omar Abdulaziz. Credit: Youtube/Yakathah Ch

In over 400 WhatsApp messages exchanged by Abdulaziz and Khashoggi a year before the murder, the journalist describes the Saudi crown prince as a "beast" and a "pac-man" devouring everyone in his path, including his own supporters.

CNN was given exclusive access to the correspondence between the two by Abdulaziz, who shared the text messages, voice notes, pictures and videos that he had exchanged with Khashoggi.

The correspondence highlights the late journalist's unrestrained criticism of crown prince, as Abdulaziz told CNN: "[Jamal] believed that MBS is the issue, is the problem and he said this kid should be stopped."

The correspondence, which happened on a daily basis between October 2017 and August of this year, shows that Abdulaziz and Khashoggi planned to set up an online movement of Saudi youth that would fight the Saudi regime's propaganda on social networks.

Making use of Khashoggi's established profile, the pair managed to garner 340,000 followers on Twitter. But in August, two months before Khashoggi's murder, the journalist began to suspect that the Saudi government had access to their correspondence. "God help us," Khashoggi wrote, upon realizing that the Saudi government knew about their online movement.

Abdulaziz's lawsuit against NSO comes after a Haaretz investigation revealed revealed that the company negotiated with Saudi Arabia the sale of advanced cyber attack capabilities.

According to a complaint that currently being looked into, NSO offered Saudi intelligence officials the use of a system that would let them hack cellphones, several months before the Saudi crown prince began his purge against dissidents.

Around the time the report was published, Amnesty International Israel asked the Defense Ministry to revoke cyber firm NSO's defense export license, saying it had been proven that its software had been used in "a series of egregious human rights violations."

NSO responded to accusations of misuse, saying that their software is fully vetted and licensed by the Israeli government. "Our products have a long track record of assisting governments in preventing suicide bombers, stopping drug lords and sex traffickers, and helping safely return victims of kidnapping," the statement said.

"If there is suspicion of misuse, we investigate it and take the appropriate actions, including suspending or terminating a contract," it adds.