A French journalist has been detained by French police in connection with a 2021 report which alleged that French intelligence was used by Egypt to target and kill civilians.
Police reportedly searched Ariane Lavrilleux's house on 19 September and later took her into custody.
Her lawyer said Lavrilleux was being questioned as part of an investigation into compromising national security.
Amnesty International France has condemned the arrest.
"We're very worried," said Amnesty's Katia Roux. "To put in police custody a journalist for doing her job, moreover for revealing information of public interest, could be a threat to freedom of the press and confidentiality of sources."
Lavrilleux is reportedly being questioned by police officers from the French intelligence service - the General Directorate for Internal Security, or DGSI.
Her 2021 report used leaked classified documents to allege that Egyptian authorities used French intelligence to bomb and kill smugglers on the Egyptian-Libyan border between 2016 and 2018.
According to the report, French forces were implicated in "at least 19 bombings" against civilians.
It was published by Disclose, a French investigative journalism website.
Disclose said that French authorities under the presidencies of President François Hollande and President Emmanuel Macron were "constantly informed" of the developments by staff at "several military departments", but that their concerns were ignored.
At the time of publication, Disclose acknowledged that the report included national security secrets but said that it was sharing them "in the name of a fundamental principle of democracy: the right to information".
"The notion of 'classified information' cannot be invoked to protect a campaign of arbitrary executions against civilians," Disclose said.
It also said that, by publishing the report, it was knowingly taking the risk to "contravene the law".
After the articles were published, France's armed forces ministry filed a legal complaint for "violation of national defence secrets".
The Committee to Protect Journalists (CPJ) called for Ms Lavrilleux's release, asked that all criminal investigations against her are dropped and said police should refrain from questioning her over her sources.
"Journalists must be able to freely report on national defence and security issues. Questioning reporters about their confidential sources places them under unwarranted pressure and could have a chilling effect on defence reporting," said Attila Mong, CPJ's Europe representative.
