French police arrested Pavel Durov, the billionaire founder and CEO of the messaging app Telegram, at Le Bourget airport near Paris on Saturday.
Durov was arrested on a warrant for offenses related to the popular messaging app, the AFP news agency reported, citing unnamed officials.
According to French broadcaster TF1, Durov was traveling aboard his private jet from Azerbaijan and was arrested around 8 p.m. local time (1800 GMT).
He is due to appear in court on Sunday.
Why is Durov being investigated?
Durov is suspected of failing to take measures to curb the use of his platform for criminal purposes.
France's OFMIN, an agency tasked with preventing violence against minors, had issued an arrest warrant for Durov as part of a preliminary investigation into alleged offenses including fraud, drug trafficking, cyberbullying, organized crime and the promotion of terrorism, one of the sources close to the case said.
"Enough of Telegram's impunity," said one of the investigators. He added that they were surprised that Durov came to Paris, knowing that he was a wanted man.
What is Telegram?
Telegram is one of the most important social media platforms in the world after Facebook, YouTube, WhatsApp, Instagram, TikTok and Wechat. It currently has the aim of reaching one billion active users by next year.
The Russian-born Durov, 39, reportedly holds French citizenship. He founded Telegram in 2013 with his brother Nikolai.
Durov left Russia in 2014 after refusing to comply with government demands to shut down opposition communities on his social media platform, VK, which he subsequently sold.
After Russia launched its full-scale invasion of Ukraine in 2022, Telegram became the main source of unfiltered, sometimes graphic and misleading content from both sides about the war and the politics surrounding the conflict.
How is Russia reacting to Durov's arrest?
Following reports of Pavel Durov's arrest in France, the Russian Embassy in France is taking "immediate steps" to clarify the situation, Russian state news agency TASS reported.
"Do you think ... they will appeal to Paris and demand Durov's release, or will keep their lips sealed?" Russian Ministry spokesperson Maria Zakharova said on Telegram.
The messaging app is one of the most important online networks in Russia. It is used by many authorities and politicians for communication.