French President Emmanuel Macron insisted on Monday afternoon that the arrest of Telegram CEO Pavel Durov was part of an ongoing judicial investigation rather than a political move.

The statement is the first official confirmation of the Russian billionaire's arrest, nearly two days after Durov was detained when his private jet landed at an airport outside of Paris on Saturday.

Moscow has since accused France of free speech double standards and prompted a firm warning from the Kremlin that Durov should be accorded his rights, further aggravating the already tense relations between both countries.

Numerous questions have been raised about the reasons and circumstances of his arrest.

On Sunday night, French authorities extended Durov's detention for allegedly not curbing offences such as fraud, drug trafficking, organised crime and promotion of terrorism on the Telegram messaging platform, according to French media reports.

Durov could be held up to a maximum of 96 hours for questioning. Once the detention phase ends, the judge can then decide to free him or press charges.

Russia's embassy in Paris said it had demanded access to Durov but said "the French side is refusing to cooperate" since Durov is also a French citizen.

Macron said that while France is "deeply committed to freedom of expression and communication" such freedoms are "upheld within a legal framework, both on social media and in real life".

"It is up to the judiciary, in full independence, to enforce the law," he said on X.

"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."

Durov himself left Russia in 2014 after he refused to comply with demands to shut down opposition communities on the VKontakte social media platform, which he also founded and has since sold.