Australia's internet regulator said on Thursday it ​had begun legal action against messaging platform Telegram ‌over alleged failings to tackle pro-terror posts.

The office of the eSafety Commissioner said it had begun action after Telegram failed to remove ​videos of terrorist executions and mass shootings.

"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," eSafety ​Commissioner Julie Inman Grant said in a statement.

"We allege that this content remained accessible on the service long after Telegram had been put ​on notice."

Failure to comply with Australia's codes and standards ​could result in civil penalties of up to A$54.6 million ($38 million), the ‌statement ⁠said.

A spokesperson for Telegram did not immediately respond to a request for comment.

Telegram is one of the world's most downloaded apps, with over 1 billion monthly active users, according ​to the company.

Its ​founder, Russian-born Pavel ⁠Durov, left Russia in 2014, moving himself and the company to Dubai in 2017.

The platform ​has become a critical source of information on ​Russia's ⁠war in Ukraine and is used widely by officials in Moscow and Kyiv.

Russia on Wednesday charged Durov with facilitating terrorist activity, ⁠alleging ​that the app was being used ​by Ukrainian spies to organise attacks inside Russia.