France, July 30 -- Russian-born Durov, a serial tech founder who has lived outside Russia for years and holds French and United Arab Emirates passports, has frequently clashed with the Russian authorities, as Moscow has tightened its grip on the internet.

His Telegram messenger service is one of the country's main communications platforms, and officials have repeatedly tried to block access or thwart its success in a bid to pressure Durov into handing over user data, or to push Russians towards using an unencrypted, state-backed alternative. Founder and CEO of Telegram Pavel Durov delivers a keynote speech during the Mobile World Congress in Barcelona, Spain, in February 2016.

The FSB security service said it had launched international ...