Azerbaijan authorities arrested a Frenchman on espionage charges in December, the Azerbaijani ambassador to France told AFP on Tuesday, amid rising tensions between both countries and tit-for-tat expulsions.
Baku has accused France of supporting Azerbaijan's arch-enemy Armenia, both diplomatically and militarily, and of seeking to fuel tensions in the South Caucasus.
"Suspected of having committed acts of espionage, Martin Ryan, a French national, was arrested on December 4, 2023," said Azerbaijan's ambassador Leyla Abdullayeva.
She said judicial authorities had ordered that he be detained for four months. The French embassy in Baku was notified, she added.
The French foreign ministry confirmed that a French national was being held in Azerbaijan.
"We consider this detention to be arbitrary, and ask for our fellow national to be freed without delay," the ministry said.
Ryan's father Richard said the family had spoken to him.
"We spoke to him four times, each time for two minutes," he told AFP. "He says he's being treated well and is getting on well with his lawyer."
According to his father, Ryan believes his detention to be linked to the tensions between the two countries.
"Once he told me: 'They wanted to use me as a pawn'," Richard Ryan said.
On Tuesday, the Frenchman's court-appointed lawyer, Nizami Aliyev, told AFP that Ryan could face up to 15 years in prison, if convicted.
He said he could not share any information and stressed it was "risky to talk about the case."
Aliyev also claimed that Ryan had been in contact with French people who he later learned were "agents" of French intelligence.
"Martin is not an agent, he is a citizen," the lawyer said.
Diplomatic tensions between Paris and Baku escalated at the end of December, when Azerbaijan ordered two French diplomats to leave the country.
France declared two Azerbaijani diplomats "persona non grata" as a reciprocal measure.
In November, Azerbaijani President Ilham Aliyev accused France of inciting conflict in the Caucasus by arming Armenia.
Azerbaijan and Armenia have in the last three decades fought three wars over the region of Nagorno-Karabakh, which was seized by Armenian forces when the Soviet Union fell apart.
In the latest war, Azerbaijan took total control of Karabakh in a surprise offensive last year.
The move sparked some international condemnation, including from France, but also hope of a settlement to end years of conflict between Baku and Yerevan.
Paris has also linked Azerbaijani figures to a disinformation campaign aimed at tarnishing France's reputation as host of the 2024 Olympic Games, according to a report seen by AFP in November. France is home to a large Armenian diaspora.