Telegram gave no details of the arrest but said the Dubai-based company abided by European Union laws and its moderation was "within industry standards and constantly improving".
"Telegram's CEO Pavel Durov has nothing to hide and travels frequently in Europe," Telegram said in a statement. "It is absurd to claim that a platform or its owner are responsible for abuse of that platform."
When asked about his arrest, the Kremlin on Monday said it had yet to see any official French accusations against Durov.
"We do not yet know what exactly Durov is accused of," Kremlin spokesman Dmitry Peskov told a news briefing.
"With what exactly are they trying to incriminate Durov? Without (knowing), it would probably be wrong to make any statements," Peskov said.
The Russian embassy in Paris said on X that French authorities had declined to cooperate with its requests for consular access, but said it was in contact with Durov's lawyer. The embassy did not respond to a request for comment.
FRENCH CITIZEN
Telegram was founded by Durov, who left Russia in 2014 after he refused to comply with demands to shut down opposition communities on his VK social media platform, which he has sold.
The encrypted application, with close to 1 billion users, is particularly influential in Russia, Ukraine and the republics of the former Soviet Union. Durov, who was born in Soviet Leningrad and graduated from St Petersburg State University, lists his political views as "libertarian".
He obtained his French passport in 2021 through a special procedure for high-profile foreigners exempting them from the usual legal requirements, including having lived in the country for at least five years.
The French foreign ministry, which is in charge of the procedure, did not immediately reply to a Reuters request for comment. The Elysee presidential office also declined to comment, deferring to the foreign ministry.
According to French law, any foreigner can be handed citizenship under the special rules provided he speaks French and "contributes through his outstanding work to France's influence and the prosperity of its international economic relations".
Durov never lived in France and it was unclear what special link he had to the country. On June 10, Durov posted in his Telegram channel: "As a French citizen, I agree that France is the best holiday destination."
His naturalization procedure is rare, with only 10-20 cases processed each year and each one requiring high-level political support, local media have reported.
Evan Spiegel, the founder of Snap
(SNAP.N) the maker of the Snapchat app, received French citizenship in 2018 under the same programme, local media reported at the time. Snap did not respond to request for comment.
Russian state media reported that Durov also had the citizenships of Russia and of St Kitts and Nevis. Reuters was unable to verify those reports.
Source: Reuters