Pavel Durov, the billionaire founder of messaging app Telegram, was arrested in France on Saturday at Le Bourget airport, near Paris.
Durov's arrest came after arriving from Azerbaijan on a private jet, and sources revealed that French police had sprung into action after seeing his name on the passenger list.
The arrest was linked to an initial investigation into allegations that Telegram failed to prevent illegal activity due to lax control over content shared by Telegram users and a lack of cooperation with law enforcement.
Telegram, which is based in Dubai, has issued a statement defending its policy of policing user content and emphasizing that Durov, who holds French and UAE citizenship, regularly travels across Europe and has nothing to hide.
The incident has drawn criticism from Moscow, with Russian lawmakers labeling Durov a political prisoner, and concerns from Elon Musk, who has stated that free speech in Europe is under threat.
Despite these claims, French authorities have yet to officially confirm the arrest.
Telegram, which is widely used across Russia, Ukraine and former Soviet republics, stands as one of the leading global social media platforms, trailing giants like Facebook and WhatsApp.