Messaging app Telegram has said its CEO Pavel Durov, who was detained in France on Saturday, has "nothing to hide".

Mr Durov was arrested at an airport north of Paris under a warrant for offences related to the app, according to officials.

The investigation is reportedly about insufficient moderation, with Mr Durov accused of failing to take steps to curb criminal uses of Telegram. The app is accused of failure to cooperate with law enforcement over drug trafficking, child sexual content and fraud.

Telegram said in a statement that "its moderation is within industry standards and constantly improving".

"It is absurd to claim that a platform or its owner is responsible for the abuse of that platform," the app said.

Telegram said Mr Durov travels in Europe frequently and added that it abides by European Union laws, including the Digital Services Act, which aims to ensure a safe and accountable online environment.

"Almost a billion users globally use Telegram as a means of communication and as a source of vital information," the app's statement read.

"We’re awaiting a prompt resolution of this situation. Telegram is with you all."

Judicial sources quoted by AFP news agency say Mr Durov's detention was extended on Sunday and could last as long as 96 hours.

Pavel Durov, 39, was born in Russia and now lives in Dubai, where Telegram is based. The Russian citizen also holds citizenship of the United Arab Emirates and France.

Telegram is particularly popular in Russia, Ukraine and former Soviet Union states.

The app was banned in Russia in 2018, after a previous refusal by him to hand over user data. The ban was reversed in 2021.

Telegram is ranked as one of the major social media platforms after Facebook, YouTube, WhatsApp, Instagram, TikTok and Wechat.

Mr Durov founded Telegram in 2013. He left Russia in 2014 after refusing to comply with government demands to shut down opposition communities on his VKontakte social media platform, which he sold.

Russia's foreign ministry said the Russian embassy to France had "immediately taken the steps required in such cases to clarify the situation around the Russian citizen, despite not having received a request from the businessman's representatives".

Then embassy itself said it was seeking to "clarify the reasons for the detention and to provide for the protection of Mr Durov’s rights and facilitate consular access".

It added that the French authorities had not been cooperating with Russian officials.

Russian foreign ministry spokeswoman Maria Zakharova posted on Telegram asking whether Western human rights NGOs would be silent on Mr Durov's arrest after they criticised Russia’s decision to “create obstacles” to the work of Telegram in Russia in 2018.

Telegram allows groups of up to 200,000 members, which critics have argued makes it easier for misinformation to spread, and for users to share conspiracist, neo-Nazi, paedophilic, or terror-related content.

In the UK, the app was scrutinised for hosting far-right channels that were instrumental in organising the violent disorder in English cities earlier this month.

Telegram did remove some groups, but overall its system of moderating extremist and illegal content is significantly weaker than that of other social media companies and messenger apps, say cybersecurity experts.