French President Emmanuel Macron convened an urgent national security meeting on Thursday - after his own phone was identified as being a potential target of the Israeli Pegasus spyware.
A group of international media organisations found that Pegasus, licensed by Israel technology company the NSO Group, was used in hacks of smartphones belonging to journalists, government officials and activists around the world, including France.
Macron has called for a series of investigations after the Le Monde daily reported that one of his phone numbers - along with those of 15 members of the French government - was on a list of potential targets in 2019.
However without analysing Macron's phone itself, the journalists could not confirm whether a successful hack had taken place.
Hacking from Morocco
Evidence of an attempt was found on a device used by former environment minister Francois de Rugy, who is close to Macron.
Use of the spyware to target French officials allegedly originated in Morocco, which has also been accused of targeting several high-profile French journalists with the software.
Paris prosecutors opened an investigation following complaints filed by news site Mediapart and the satirical newspaper Le Canard Enchaine.
The Moroccan government said it "never acquired computer software to infiltrate communication devices".
Radio France journalists found that Morocco's King Mohammed VI and other members of the royal family were targeted by a Moroccan client of NSO.
The NSO Group has denied that Macron was among its clients' targets.
Both the company and the Israeli Defence Ministry, which oversees its exports, say that Pegasus is meant to be used to track terrorists and criminals, and that the only foreign clients are vetted governments.
NSO chief Shalev Hulio told Israeli Army Radio on Thursday that the company has worked with 45 countries and rejected around 90 others as potential clients, and it has also shut down five Pegasus systems for abuse.