"This case concerns content linked to some of the most notorious acts of known extremist violence in recent history, including material associated with the Christchurch and Buffalo terror attacks. We allege that this content remained accessible on the service long after Telegram had been put on notice," eSafety Commissioner Julie Inman Grant said in a July 30 statement.

"With the painful aftermath of the Bondi terror attack still fresh in the minds of all Australians, and ASIO's assessment that Australia's terrorism threat level remains 'probable', it is more important than ever that digital platforms meet their obligations to protect the community.”

In the course of its investigation, eSafety found Telegram had failed to comply with its obligations under the Online Safety Act's Relevant Electronic Services Standard in several areas:

Failing to remove publicly posted pro-terror material and other unlawful material after becoming aware of it. Specifically, Telegram failed to remove material, such as videos of terrorist executions, after reports by Australian end-users were made, with material remaining available for up to three weeks;

Failing to minimise the risk of future breaches, such as by removing the relevant accounts, channels and groups after becoming aware of pro-terror material and other unlawful material;

Failing to detect known pro-terror material such as the live streamed Christchurch Mosque shooting from 2019, and the Buffalo mass shooting in New York from May 2022, with such material having been uploaded to Telegram nearly 3 months prior to its removal.

Failing to effectively disrupt and deter the distribution of pro-terror material.

Failing to have Terms of Service that prohibited users from accessing or distributing pro-terror material on all parts of Telegram.

Failing to inform complainants of the outcome of their complaints about unlawful material.

Inman Grant said the continuing proliferation of “pro-terror material” posed the risk of normalising such content, causing harm to Australians, and even radicalisation & recruitment of at-risk persons.

"ASIO Director General Mike Burgess has recently stated that online radicalisation is playing an increasing role in ASIO investigations, and 'instead of being radicalised by associates in the real world, individuals are often being radicalised by strangers online' and specifically warned about the risks on Telegram,” Inman Grant said.

"This should concern all of us. We're talking about the most seriously harmful online material and Australian law requires services across the online ecosystem to take responsibility for the role they play in allowing this material to be disseminated, including by enforcing their own terms of service.

"Telegram reports having more than a billion users worldwide and is a widely used service in Australia, visited by Australians on average 1.5 million times a month. It provides groups for up to 200,000 users, as well as channels for wider 'broadcasts' with no maximum limit and as such, Telegram has a responsibility to take reasonable steps to prevent the hosting, sharing, amplification and monetisation of this harmful material.

"No platform is above the law and this action demonstrates that eSafety will not hesitate to use the full range of its powers to protect Australians."

Telegram could face fines of up to $54.6 million.

eSafety’s move comes at the same time Telegram’s founder, Pavel Durov, is facing pro-terrorism charges laid by Russian authorities.

Russia’s Federal Security Service has accused the platform of failing to remove various chats, channels, and bots used by “Ukrainian intelligence agencies, terrorist and extremist organisations to prepare and coordinate acts of sabotage and terrorism, mass murder, and cyber fraud”.

If convicted, Durov could be sentenced to life in prison.

Durov currently resides in Dubai.