Australia is taking Telegram to court over its alleged failure to remove "pro-terror" material, including video of the Christchurch shootings, the country's eSafety commissioner has said.

Julie Inman-Grant, who last year led Australia's world-first ban on social media for under-16s, said the platform faced a fine of up to to A$54.6m (£28m, US$38m) for failing to comply with its safety obligations under the Online Safety Act.

The platform had left content "linked to some of the most notorious acts of known extremist violence in recent history" online long after it had been put on notice, she alleged.

"This should concern all of us," she said, adding "no platform is above the law".

The announcement comes a day after Russia charged Telegram's founder Pavel Durov with facilitating terrorism, based on allegations that the messenger app had been used for recruitment by Ukrainian secret services.

Durov was also arrested and placed under formal investigation in France in 2024 for his alleged failure to properly moderate the app to reduce criminality. He was allowed to go home months later, while the investigation continues.

Inman-Grant said her agency had begun inquiring what Telegram was doing to combat terrorist and extremist material in March 2024, and had endured "five very difficult months of unresponsiveness".

Though the platform later started engaging, she said it had retained a "permissive environment" for hosting extremist content that was "very easy to find".

"This only serves to desensitise, to normalise and to sometimes radicalise" users, she said. She also alleged that the platform was "sometimes used to plan attacks".

A Telegram spokesperson said the platform's "extensive" anti-terrorism efforts were "well documented", adding: "We reject these allegations and will contest them in court."

Extremist content that was allegedly accessible on Telegram included video of the 2019 Christchurch mosque and Buffalo shooting in New York in May 2022, as well as videos of terrorist executions, according to Inman-Grant.

With the "painful aftermath" of the attack that targeted a Jewish festival in Bondi in December fresh in Australians' minds, it "is more important than ever that digital platforms meet their obligations to protect the community", she said.

Inman-Grant noted that Australia does not issue licences for platforms like Telegram, but said "we could apply to the federal court and ask that the service be ceased".

"We've never used those powers," she said. "We'll see how this all plays out and whether that kind of action is warranted."

The eSafety regulator also fined Telegram A$1m in February 2025 for failing to respond on time to questions about how it was tackling child abuse and extremist material on the platform.