Special counsel Robert Mueller on Thursday subpoenaed a former aide to Trump adviser Roger Stone, The New York Times reported.
The special counsel reportedly called for Andrew Miller, who worked for Stone during the 2016 campaign, to appear before a grand jury in the investigation into Russian meddling in the election.
Attorney Paul Kamenar, who is believed to be representing Miller, told the Times that he intends to fight the subpoena by arguing Mueller’s appointment was unconstitutional. Others have made similar claims, thus far unsuccessfully.
Miller is the third ex-Stone associate who has reportedly been subpoenaed in the Mueller investigation.
Former Stone aides John Kakanis and Jason Sullivan have also been called to appear before a grand jury.
Stone has been a central figure in the special counsel’s investigation. He worked briefly on the Trump campaign and has since served as an adviser to the president.