Pavel Durov, the head of Telegram, has had his detention extended until August 28, according to a source from the AFP news agency.
Durov, who was born in Russia, was detained at Le Bourget Airport near Paris on August 24.
The French department for preventing violence against minors issued an arrest warrant against him in connection with an investigation into crimes including fraud, drug trafficking, organized crime, and the promotion of terrorism.
Under French law, after 96 hours, Durov must be either released or formally charged by the competent authorities.
