A lawyer appointed to help review documents seized from President Donald Trump's former lawyer has billed a federal court more than $338,000 for legal work on the case in May alone.

Barbara Jones is helping to determine which of the records and electronic files seized from ex-Trump attorney Michael Cohen by the FBI in April are protected by attorney-client privilege. She submitted her invoice to U.S. District Court in Manhattan on Wednesday.

Jones is a former federal judge. Lawyers for Cohen and the Republican president have been going through millions of data files and paper records seized in the raid looking for information they believe should be withheld for investigators.

Prosecutors have said they are investigating Cohen's personal business dealings.