A probe by Attorney General William Barr into the origins of the Russia investigation has changed from an administrative review into a criminal investigation, a person familiar with the review confirmed to NBC News.

The review is being conducted by Connecticut U.S. Attorney John Durham. The New York Times first reported Thursday that the administrative review has turned into a criminal investigation.

It’s not clear when the change occurred, but the probe began in May as an administrative review.

The Times reported that the change in status gives Durham the power to subpoena witness testimony and documents, to impanel a grand jury and to file criminal charges.

President Donald Trump has repeatedly called the Russia investigation conducted by special counsel Robert Mueller a "witch hunt."

Republicans have suggested the investigation stemmed from a plot by members of the Obama Administration and career intelligence officials, in what they call the "Deep State," to undermine Trump.