Telegram boss Pavel Durov could be held in police custody until Wednesday after French prosecutors said they had granted extra time for questioning, while a senior ally of Russian President Vladimir Putin alleged Washington was behind his arrest.
Durov, a Russian-born billionaire, was arrested in France over the weekend as part of an investigation into crimes related to images of child sex abuse, drug trafficking and fraudulent transactions on the platform, French prosecutors said on Monday.
On Tuesday, a spokesperson for the public prosecutor said Durov's detention had been extended by up to 48 hours late on Monday.
The messaging platform, which analysts have described as a virtual battlefield, has been heavily used by both sides of the war in Ukraine and war-related news and propaganda channels around the globe.
Without providing evidence, Vyacheslav Volodin, the chairman of Russia's State Duma, the lower house of parliament, said the United States, through France, was attempting to exert control over Telegram.
"Telegram is one of the few, and at the same time the largest, Internet platform over which the United States has no influence," Volodin said in a post.
"On the eve of the U.S. presidential election, it is important for (President Joe) Biden to take Telegram under control."
The White House did not immediately comment on Durov's arrest.
With nearly 1 billion users, Telegram, which presents itself as a haven for free speech and political dissidents, is particularly prominent in Russia, Ukraine and the republics of the former Soviet Union.
While millions of ordinary users like the app for its easy use and range of functions, it is also widely used by far-right, anti-vax and conspiracist movements.
French President Emmanuel Macron, who is known to be an avid user of the app, has said that the arrest was "in no way a political decision."
After Russia launched its invasion of Ukraine in 2022, Telegram has become the main source of unfiltered - and sometimes graphic and misleading - content from both sides about the war and the politics surrounding the conflict.
