An associate of Roger Stone Roger Jason StoneThe agony of justice Our Constitution is under attack by Attorney General William Barr Justice IG investigating Stone sentencing: report MORE has been held in contempt for refusing to testify before the grand jury in special counsel Robert Mueller Robert (Bob) MuellerCNN's Toobin warns McCabe is in 'perilous condition' with emboldened Trump CNN anchor rips Trump over Stone while evoking Clinton-Lynch tarmac meeting The Hill's 12:30 Report: New Hampshire fallout MORE’s investigation, according to The Washington Post.

U.S. District Chief Judge Beryl Howell ordered Andrew Miller to be held in contempt after a sealed hearing on Miller's refusal to not testify before the grand jury. She placed a stay on that order until Monday, as his lawyers file an appeal.

Miller's attorney Paul Kamenar told the Post that his client was “held in contempt, which we asked him to be in order for us to appeal the judge’s decision to the court of appeals.”

ADVERTISEMENT

Miller had previously challenged the subpoena ordering him to testify before the grand jury, arguing that Mueller's appointment as special counsel was unconstitutional. Howell rejected that argument in a 93-page opinion earlier this month, ordering him to appear before the grand jury and hand over documents in the probe.

Stone, a longtime confidant of Trump's, has long been a person of interest in the special counsel's probe: Several of his associates have been subpoenaed in the investigation in recent weeks.

Prostitution mogul Kristin Davis, nicknamed the "Manhattan Madam," who has a close relationship with Stone, will also reportedly testify before Mueller's grand jury and reportedly voluntarily met with the special counsel's team.

Stone himself has not yet been questioned or subpoenaed in the investigation.

He said last month that he believes he is an unnamed person referred to in Mueller's indictment last month of 12 Russian military officers in the 2016 Democratic National Committee (DNC) hack.