WASHINGTON, DC, USA (AFP) — Special counsel Robert Mueller has impanelled a grand jury to investigate Russia’s interference with the 2016 presidential election, The Wall Street Journal reported yesterday — a step toward possible criminal indictments.

The newspaper, citing two unnamed sources familiar with the matter, reported that the grand jury had begun its work here in the US capital “in recent weeks”.

The move is a sign that the sweeping federal investigation — which includes allegations that Trump campaign officials coordinated with Russia to tilt the election in the Republican’s favour — is gathering pace.

The establishment of a grand jury will allow Mueller, a former FBI director, to subpoena documents and get sworn testimony. It could lead to criminal indictments.

“It’s a significant escalation of the process,” national security attorney Bradley Moss told AFP.

“You don’t impanel a grand jury unless your investigation has discovered enough evidence that you feel reflects a violation of at least one, if not more, criminal provisions,” he said.

“If you secure an indictment, your next step is to arrest the defendant.”

Presidential lawyer Ty Cobb said he was not aware that a grand jury had been convened.

“Grand jury matters are typically secret,” Cobb said, adding that “the White House favours anything that accelerates the conclusion of his work fairly”.