PARIS: Pavel Durov, the founder and chief of Telegram, was to appear in a French court Wednesday to face possible charges of failing to curb extremist and illegal content on the popular messaging app after his arrest at the weekend.

Russian-born Durov, 39, was arrested at Le Bourget airport outside Paris late Saturday.

After almost four days of questioning in detention by French investigators he was handed over to judicial authorities who will decide further measures, a source close to the case told AFP.

A Paris investigating magistrate will decide whether to press charges against Durov, and the judiciary would then rule on whether he will be remanded in custody or allowed to go free, possibly under judicial control with restrictions on his movements.

As part of a probe that was confidentially opened on July 8, Durov is being investigated on suspicion of 12 offences related to failing to curb extremist and criminal content on Telegram, sources close to the investigation have said.

The tech mogul founded Telegram as he was in the process of quitting his native Russia a decade ago. Its growth has been exponential, with the app now reporting over 900 million users.

An enigmatic figure who rarely speaks in public, Durov is a citizen of Russia, France and the United Arab Emirates, where Telegram is based.

Forbes magazine estimates his current fortune at $15.5 billion, though he proudly promotes the virtues of an ascetic life that includes ice baths and not drinking alcohol or coffee.

Numerous questions have been raised about the timing and circumstances of Durov’s detention, with supporters seeing him as a freedom of speech champion and detractors as a menace who wilfully allowed Telegram to get out of control.