French prosecutors are expected to charge or release the chief executive of the popular messaging app Telegram, Pavel Durov, after his police custody order expires.

Durov was detained on Saturday at Le Bourget airport outside Paris as part of a judicial inquiry opened last month involving 12 alleged criminal violations.

They include allegations that his platform is being used for selling child sexual abuse material and drug trafficking, fraud, and abetting organised crime transactions, as well as claims that Telegram refused to share information or documents with investigators when required by law.

Under French law, Durov can be held in custody for questioning for up to 96 hours after the arrest.

The Paris prosecutor’s office said in a statement that Durov’s police custody order was extended on Monday evening for up to 48 hours. After that, authorities must release or charge him.

His arrest in France has caused outrage in Russia, with some government officials calling it politically motivated and proof of the West’s double standard on freedom of speech.

The outcry has raised eyebrows among Kremlin critics because in 2018, Russian authorities themselves tried to block Telegram but failed, withdrawing the ban in 2020.

In Iran, where Telegram is widely used despite being officially banned after years of protests challenging the country’s Shia theocracy, Durov’s arrest in France prompted comments from the Islamic Republic’s supreme leader.

Ayatollah Ali Khamenei weighed in with veiled praise for France for being “strict” against those who “violate your governance” of the internet.

French President Emmanuel Macron said on Monday that Durov’s arrest was not a political move but part of an independent investigation.

Mr Macron posted on X that his country “is deeply committed” to freedom of expression but “freedoms are upheld within a legal framework, both on social media and in real life, to protect citizens and respect their fundamental rights”.

In a statement posted on its platform after Durov’s arrest, Telegram said it abides by EU laws, and its moderation is “within industry standards and constantly improving”.

“It is absurd to claim that a platform or its owner are responsible for abuse of that platform,” Telegram’s post said.

“Almost a billion users globally use Telegram as means of communication and as a source of vital information. We’re awaiting a prompt resolution of this situation. Telegram is with you all.”

Durov is a citizen of Russia, France, the United Arab Emirates and the Caribbean island nation of St Kitts and Nevis.

The UAE foreign ministry said it is “closely following the case” and had asked France to provide Durov “with all the necessary consular services in an urgent manner”.

Kremlin spokesman Dmitry Peskov said he hoped that Durov “has all the necessary opportunities for his legal defence” and added that Moscow stands “ready to provide all necessary assistance and support” to the Telegram CEO as a Russian citizen.

“But the situation is complicated by the fact that he is also a citizen of France,” Mr Peskov said.