An Australian court has upheld a fine against Elon Musk's X Corp after it admitted to failing to comply with child safety measures, resolving a three-year legal battle.

The country's internet regulator eSafety had first issued the fine in 2023, after the social media giant did not respond adequately to a request to supply information on how it was tackling the exploitation of children online.

But X had argued that it did not have to comply with the request because it had come before Twitter, as it was then known, merged with X Corp and that Twitter was no longer a company.

On Thursday it admitted wrongdoing and has been ordered to pay a A$650,000 ($463,000, £345,000) fine.

Justice Michael Wheelahan raised the initial fine of A$610,00 and also ordered the US company to pay A$100,000 towards the regulator's legal costs.

"A penalty near the maximum is appropriate in the case of the respondent, which is a substantial corporation so that it operates as a real deterrent and is not simply a cost of doing business," Wheelahan said.

Australia's e-regulator has previously clashed with X, including over its world-leading ban on social media for under-16s and its refusal to remove videos of a stabbing that took place in a Sydney church.

eSafety Commissioner Julie Inman Grant told the BBC in 2024 she had received death threats and her children were doxxed after Musk called her the "censorship commissar" in a post to his 196 million followers.

"Meaningful transparency is critical to holding technology companies to account," Grant said in a statement on Thursday.

The request for information on how the social media platform was tackling the spread of child sexual abuse content was first issued to Twitter in February 2023, and it merged with X a month later.

Lats year the court upheld an earlier ruling that X was required to respond to the transparency notice and on Thursday the parties agreed to the penalty, which must be paid within 45 days.