Andrew Miller still fighting special counsel subpoena, in limbo after Mueller wraps investigation

Special counsel Robert Mueller (L) arrives at the U.S. Capitol for closed meeting with members of the Senate Judiciary Committee June 21, 2017 in Washington, DC. The committee meets with Mueller to discuss the firing of former FBI Director James Comey.  (Photo by Alex Wong/Getty Images)

(CNN)Andrew Miller, believing he may still be wanted to testify against Roger Stone to a grand jury, will continue to "pursue further judicial review" of his court losses after he challenged the constitutionality of Robert Mueller as special counsel, his attorney said on Friday after Mueller announced his investigation's end.

Miller, a former aide to Stone, was subpoenaed last year to turn over digital records and testify to a federal grand jury, but he refused to testify and was held in contempt of court. A judge ordered him to jail for failing to comply with the subpoena, but that has been on hold as he appealed. The DC Circuit Court of Appeals ruled against him in late February. Miller has not yet taken action in court regarding what he plans next.
He hasn't yet been told by prosecutors that he's no longer needed as a witness, his attorney said.
"We are pursuing further judicial review of our challenge to Mueller's constitutional authority to issue his subpoena last June despite today's action that indicates the special counsel has terminated his investigation," said Paul Kamenar, Miller's attorney.
    "Regardless of today's action, the National Legal Policy Center will continue to support the legal challenge to the subpoena and Mueller's authority," added Peter Flaherty, chair of the center.
    A spokesman from the special counsel's office declined to comment on Miller on Friday night.
    Before Stone was indicted, the prosecutors sought information Miller had about Stone, WikiLeaks, Julian Assange, the Democratic National Committee and the online monikers the Russians used after they hacked the Democrats.
      The DC US Attorney's Office is assisting Mueller's team in the case against Stone, which is headed to trial. It's possible Miller's matter could transfer out of Mueller's hands to the DC prosecutor's office.
      Justice Department guidelines say a grand jury can hear evidence after a person is indicted only if the grand jury continues to work on new charges -- either against that person or additional planned defendants.