The Russian national, born in 1984, was detained on suspicion of "organising events likely to lead to destabilisation" in France, a source in the state prosecution service, who asked not to be named, told AFP. The source added that the crime was punishable by up to 30 years in jail.

Prosecutors said a visit to the man's home "at the request of the interior ministry" had uncovered evidence of the suspected plans. They did not give any details of the alleged plot, except to say that specialist anti-terrorist prosecutors were not following the case.

Back on Saturday, Olympic chiefs had expressed their worries that Russian disinformation was inevitable ahead of Paris 2024, the International Olympic Committee even acknowledging that it was resigned to the Games being targeted by attacks following recent incidents blamed on Russia.

IOC spokesman Mark Adams said he believed a campaign against the Paris Olympics was already under way as final preparations for the sports spectacular entered the home stretch. "Clearly there is a campaign of some sort going on," Adams pointed out a press conference. "It's not the first or last time that the IOC will be targeted with misinformation. It's getting more and more sophisticated. "I'm afraid it's one of those things that we have to live with…it's part of the divided world we live in."

Authorities have investigated over a million people, including athletes, coaches, journalists, volunteers, security guards and even local residents near event locations ahead of the Olympics, Interior Minister Gerald Darmanin told weekly Paris Match on Tuesday. Of those, 4,360 were denied access to the Games, with people close to Darmanin telling AFP on Sunday that 880 were barred over suspicions of foreign interference.

In recent months, several high-profile stunts have raised suspicion that foreign actors are trying to influence French public opinion or stoke divisions, notably about Russia's invasion of Ukraine or Israel's campaign in Gaza after the 7 October attack by Hamas. They include dummy coffins labelled "French soldiers in Ukraine" left by the Eiffel Tower in June and red hands tagged on Paris's main Holocaust memorial in May. In October, soon after Hamas's attack, stars of David were tagged on buildings in the Paris region, with two Moldovans suspected to be working for the Russian FSB security service later arrested.

Earlier this year, the IOC said its President Thomas Bach was targeted by hoax phone calls from  a group in Russia pretending to be representing the African Union Commission. US tech giant Microsoft's Threat Analysis Center meanwhile has said Russia has ramped up disinformation efforts against the Paris Games.

The French government’s cybersecurity agency, Anssi, also issued a stern warning on Thursday, predicting that ransomware attacks during the Paris 2024 Olympics will be "inevitable." French officials have spent the past two years gearing up to combat an unprecedented level of cyber threats that could come from various sources, including criminal organisations, state actors like Russia, ideological "hacktivists," or opportunistic gamblers.

Russia has been barred from sending a formal team to compete at the Paris Olympics following the country's 2022 invasion of Ukraine. Instead, only a small handful of Russian athletes will be allowed to take part in the Olympics competing under a neutral banner.