Elon Musk is under a federal investigation related to his $44 billion takeover deal for Twitter.

Axar.az reports that the news came from a court filing made public on Thursday about the latest in ongoing legal disputes between the billionaire and the social network.

While the filing said he was under investigation, it did not say what the focus was.

"This game of 'hide the ball' must end," the company said in the court filing.

Mr Musk did not immediately respond to a request for comment.

Twitter - which sued Mr Musk in July to force him to close the deal - said lawyers for the Tesla CEO had claimed "investigative privilege" when refusing to hand over documents it wanted.