The special counsel investigating claims of Russian meddling in the US election has begun using a grand jury in Washington, a person familiar with the probe says.
The use of a grand jury, a standard prosecution tool in criminal investigations, suggests that Robert Mueller may be taking a more aggressive approach to gathering information on possible collusion with Donald Trump’s campaign team.
The person who confirmed that Mr Mueller had turned to a grand jury was not authorised to discuss the investigation by name and spoke on condition of anonymity. The Wall Street Journal first reported the use of a grand jury.
Grand juries are common vehicles to subpoena witnesses and records and to present evidence, although they do not suggest any criminal charges are near or will necessarily be sought.
It was not clear how or whether the Washington grand jury was connected to the work of a separate one in Alexandria, Virginia. That panel has been used to gather information on Michael Flynn, Mr Trump’s former national security adviser.
Mr Mueller’s team did not return a request for comment.
But Mr Trump demanded in a tweet posted yesterday: “We won. Move on!” At a rally in Huntington, West Virginia, on Thursday he fired a host of broadsides at Democrats and investigators.
He again poured scorn on the inquiry, saying it was a “total fabrication”.
White House senior counsellor Kellyanne Conway told the Fox and Friends news programme: “We know that the nature of these investigations become fishing expeditions where you’re just throwing Jello up against the wall and hoping something will stick.”
Washington defence lawyer Jacob Frenkel called Mr Mueller’s reliance on a grand jury the “logical next step in this investigation” given that it is the traditional method for prosecutors to gather evidence.
“The use of the grand jury neither escalates, nor establishes a timeline for, the investigation,” he added.
At the Huntington rally, Mr Trump challenged Democrats to either continue their “obsession with a hoax” or begin serving the interests of the American people.
“I just hope the final determination is a truly honest one, which is what the millions of people who gave us our big win in November deserve and what all Americans who want a better future want and deserve.”
Lawyers for Mr Trump said earlier they were unaware of the existence of a grand jury and had no information to suggest the president himself was under federal investigation.
Ty Cobb, special counsel to the president, said he wasn’t aware Mr Mueller had started using a new grand jury.
“Grand jury matters are typically secret,” Mr Cobb said. “The White House favours anything that accelerates the conclusion of his work fairly. ... The White House is committed to fully cooperating with Mr Mueller.”
It was not known what witnesses might appear before the grand jury or what evidence it might be accumulating or presented with.
Mr Mueller, who worked as a prosecutor in Washington before becoming FBI director, was appointed special counsel in May by the Justice Department after FBI director James Comey was sacked.
He has since assembled a team of more than a dozen investigators, including current and former Justice Department prosecutors with experience in international bribery and organised crime.