Three people arrested in France, in a case with accusations of spying for Russia and war propaganda

French authorities have arrested three people on suspicion of spying for Russia and promoting its war propaganda as part of an investigation into a Franco-Russian association, prosecutors announced Tuesday.

The arrests come amid fears about the scale of Russian interference in Europe, with Western capitals pointing to Moscow as the Kremlin's military campaign in Ukraine drags on.

One of the people detained, a 40-year-old Russian man, was seen on CCTV pasting pro-Russian posters on the Arc de Triomphe in Paris in September, prosecutors said.

The man then reported by phone to the heads of the SOS Donbass association, a woman also in her 40s, suspected by French counterintelligence officials of trying to obtain economic information from the directors of some French companies.

The head of SOS Donbass was in the sights of French counterintelligence

The woman, who was born in Russia, had been on the radar of France's counterintelligence service, the Directorate General for Internal Security (DGSI), since at least the beginning of the year.

After the DGSI detected “actions likely to harm the fundamental interests of the nation”, an investigating magistrate was appointed in March to investigate several alleged crimes, including “collusion with a foreign power”, which is punishable by 10 years in prison.

SOS Donbass presents itself as a humanitarian organization providing aid to civilians in Donbas, a region in eastern Ukraine that is partially under Moscow's control.

The third person in the custody of the French authorities is a 63-year-old man born in the suburb of Seine-Saint-Denis in the north of Paris.

A fourth suspect, aged 58, has not been remanded in custody but is under strict supervision and required to report to the police station once a week.