Special counsel Robert MuellerRobert (Bob) MuellerSenate Democrats urge Garland not to fight court order to release Trump obstruction memo Why a special counsel is guaranteed if Biden chooses Yates, Cuomo or Jones as AG Barr taps attorney investigating Russia probe origins as special counsel MORE has reportedly subpoenaed a longtime aide to Roger StoneRoger Jason StoneBannon says he discussed how to 'kill this administration in the crib' with Trump before Jan. 6 Roger Stone served with Capitol riot lawsuit during radio interview Lawyer for 17 Jan. 6 defendants says he's been released from hospital MORE, an informal adviser to President TrumpDonald TrumpJan. 6 committee chair says panel will issue a 'good number' of additional subpoenas Overnight Defense & National Security — Presented by AM General — Pentagon officials prepare for grilling Biden nominates head of Africa CDC to lead global AIDS response MORE who is coming under heavy scrutiny in the federal investigation into Russian interference in the 2016 election.
Mueller subpoenaed John Kakanis, who has worked as an assistant to Stone in several capacities, two sources familiar with the matter told Reuters.
It's the second subpoena of a Stone associate to come to light this week.
On Wednesday, Reuters reported that Jason Sullivan, a lawyer and social media expert who has worked for Stone, received two subpoenas last week.
The FBI has questioned Kakanis as part of the investigation, particularly about the website WikiLeaks and its founder Julian Assange, as well as the hacker group known as Guccifer 2.0, one source told the news wire.
Mueller has not set a date for Kakanis to appear before a grand jury, the source told Reuters.
Kakanis's lawyer, Michael Becker, did not respond to Reuters's requests for comment.
Some of Stone’s previous remarks during the election has raised questions about his interactions with WikiLeaks, particularly when he said on Infowars radio show that he knew when WikiLeaks would disclose a trove of hacked emails — a claim he later walked back on CNN.
The hackers gave the emails to Assange, who published the materials, causing massive damage to the Clinton campaign and the Democratic campaign arm.
Stone, who has repeatedly denied any wrongdoing, blamed the media for creating “misapprehensions and misconceptions” about him in a statement to Reuters, arguing it was press reports that had triggered Mueller's interest in his involvement.
“I sincerely hope when this occurs that the grotesque, defamatory media campaign which I have endured for years now will finally come to its long-overdue end,” Stone told Reuters.
- Updated at 5:31 p.m.