Federal authorities are looking into Elon Musk's actions in connection with his $44 billion acquisition of Twitter Inc., the social media company said in a court document on Thursday.

The document mentioned that he was the focus of inquiries, but it didn't specify what kind of inquiries they were or which government agencies were conducting them.

Twitter said that Musk's lawyers had used the 'investigative privilege' to withhold the documents it had asked for when it sued Musk in July in an effort to persuade him to finalise the deal.

Musk's attorneys reportedly provided a 'permission log' outlining the documents to be withheld in late September, according to Twitter.

The log recorded that a draught email was sent to the U.S. Securities and Exchange Commission (SEC) on May 13 and a PowerPoint presentation for the Federal Trade Commission (FTC).

In its court petition, the corporation said that 'this game of 'hide the ball' must end.'

On October 6, the day before Delaware judge Kathaleen McCormick suspended the legal battle between the two parties after Musk changed his mind and declared he would move forward with the sale, a court filing asking her to order Musk's lawyers to release the documents was made.

It is Twitter's executives who are under federal investigation, according to Alex Spiro, an attorney for Musk, who told Reuters that Twitter's court petition was a 'misdirection'.

Twitter chose not to respond to Spiro's assertion. Tech news outlet The Information stated in April that the FTC was investigating whether Musk violated the antitrust reporting requirement relating to an investor's plans to be a passive or active shareholder.

However, according to a statement from Twitter in June, the acquisition agreement with Musk has already passed an antitrust review period by the FTC and US Department of Justice.

Musk has until October 28 to complete the transaction, according McCormick. A trial date will be scheduled for November if the agreement is not finalised by then.