Pavel Durov, billionaire founder and CEO of the Telegram messaging app, was arrested at the Bourget airport outside Paris on Saturday evening, TF1 TV and BFM TV said, citing unnamed sources.
Telegram, particularly influential in Russia, Ukraine and the republics of the former Soviet Union, is ranked as one of the major social media platforms after Facebook, YouTube, WhatsApp, Instagram, TikTok and Wechat. It aims to hit one billion users in the next year.
Based in Dubai, Telegram was founded by Russian-born Durov. He left Russia in 2014 after refusing to comply with government demands to shut down opposition communities on his VK social media platform, which he sold.
Durov was travelling aboard his private jet, TF1 said on its website, adding he had been targeted by an arrest warrant in France as part of a preliminary police investigation.
TF1 and BFM both said the investigation was focused on a lack of moderators on Telegram, and that police considered that this situation allowed criminal activity to go on undeterred on the messaging app.
Telegram did not immediately respond to a Reuters request for comment. The French Interior Ministry and police had no comment.
After Russia launched its invasion of Ukraine in 2022, Telegram has become the main source of unfiltered - and sometimes graphic and misleading - content from both sides about the war and the politics surrounding the conflict.
The app has become preferred means of communications for Ukraine's President Volodymyr Zelenskiy and his officials. The Kremlin and the Russian government also use it to disseminate their news. It has also become one of the few places where Russians can access news about the war.
TF1 said Durov had been travelling from Azerbaijan and was arrested at around 20:00 (18:00 GMT).
Durov, whose fortune was estimated by Forbes at $15.5 billion, said some governments had sought to pressure him but the app, which has now 900 million active users, should remain a "neutral platform" and not a "player in geopolitics".
Russia's embassy in France told the Russian state TASS news agency that it was not contacted by Durov's team after the reports of the arrest, but it was taking "immediate" steps to clarify the situation.
Russia's representative to international organisations in Vienna, Mikhail Ulyanov, and several other Russian politicians were quick to accuse France of acting as a dictatorship.
"Some naive persons still don't understand that if they play more or less visible role in international information space it is not safe for them to visit countries which move towards much more totalitarian societies," Ulyanov wrote on X.
Several Russian bloggers called for protests at French embassies throughout the world at noon on Sunday.
