American billionaire Elon Musk is under U.S. investigation concerning the troubled acquisition of Twitter, which has been ongoing for months. The social media company Twitter stated in a legal filing that Musk is under a federal investigation related to the $44 billion acquisition deal. A legal document revealed last week that a judge in the state of Delaware ordered the pause of Twitter's lawsuit against the billionaire until the 28th of this month, to allow Musk to complete the acquisition deal.