(CNN) -- Justice Department Special Counsel Robert Mueller has launched a grand jury in his investigation of Russian influence in the 2016 election, The Wall Street Journal reportedThursday.
Citing unnamed people familiar with the matter, the Journal said Mueller had impaneled the grand jury in Washington, where his team of investigators continue to look into whether President Donald Trump or any of his campaign associates colluded with Russia during the presidential contest.
The move would signal a new step in the investigation, which Trump has lambasted as a "witch hunt." Trump has denied any collusion between his team and the Russians. US intelligence agencies have concluded that Russia attempted to sway the presidential contest in Trump's favor.
In May, CNN reported that federal prosecutors had issued grand jury subpoenas to some associates of former national security adviser Michael Flynn as part of the ongoing FBI probe into the Russian meddling.
Mueller took over that investigation in mid-May.