Telegram described the allegations as “absurd” while Russian officials labelled Mr Durov’s arrest as politically motivated.
Pavel Durov, the chief executive of Telegram, is to face further investigation over allegations he allowed criminal activity on the messaging app.
French judges have barred Mr Durov from leaving France pending further investigation, but he has avoided being held in custody with a €5m bail.
The billionaire founder of the encrypted messaging and social media app was arrested in France on Saturday after his private jet landed at Le Bourget airport outside Paris.
The Russian-born entrepreneur – who became a French citizen in 2021 – is accused of operating a platform which is being used for child sexual abuse material and by organised crime gangs, for drug trafficking and fraud.
It is also claimed that Telegram refused to share information or documents with investigators.
Mr Durov faces preliminary charges which, under French law, mean magistrates have strong reason to believe a crime was committed but allow more time for further investigation.
But it might not necessarily lead to a trial.
Telegram has insisted it abides by EU laws and its moderation is “within industry standards and constantly improving”.
Its statement added: “It is absurd to claim that a platform or its owner is responsible for abuse of that platform.”
Mr Durov’s arrest in France, and four days of questioning, has caused outrage in Russia.
Paper planes – representing Telegram’s logo – being placed in Moscow in support of the billionaire.
Some government officials claim his detention was politically motivated and proof of the West’s double standard on freedom of speech.
However, Kremlin critics have pointed out that, in 2018, Russian authorities tried to block the Telegram app but failed, withdrawing the ban in 2020.
Meanwhile in Iran, where Telegram is officially banned, but still widely used, the Islamic Republic’s supreme leader, Ayatollah Ali Khamenei praised France for being “strict” against those who “violate your governance” of the internet.
It has also prompted controversial influencer Andrew Tate to compare himself to Telegram’s CEO as he fights allegations of human trafficking in Romania, among other offences, which he denies.