Roger Stone, the longtime informal adviser to Donald Trump, has been arrested on charges brought by Robert Mueller, the special counsel’s office said on Friday.
Mr Stone, 66, was charged with seven counts related to congressional testimony he gave about his contacts with WikiLeaks during the 2016 presidential campaign.
The charges included five counts of making false statements, one count of obstruction of an official proceeding, and one count of witness tampering.
Robert Buschel, an attorney for Mr Stone, did not immediately return a request for comment.
The indictment on Friday accused Mr Stone of lying to the House intelligence committee, which was investigating his efforts during the campaign to contact Julian Assange, the founder of WikiLeaks who resides in the Ecuadorean embassy in London.
Mr Stone, a longtime Republican political operative, had served on the Trump campaign until August 2015, and then maintained “regular contact” thereafter, according to the special counsel’s office.
In July 2016, Mr Assange published a trove of stolen documents from the Democratic National Committee, which had been hacked by Russian intelligence, according to a previous indictment by Mr Mueller.
The charges suggested that Mr Stone may have had some knowledge that WikiLeaks had the stolen documents prior to their release and had informed the Trump campaign.
“By in or around June and July 2016, Stone informed senior Trump campaign officials that he had information indicating [WikiLeaks] had documents whose release would be damaging to the Clinton campaign,” the indictment alleged.
The indictment went on to claim that, following the initial release of documents on July 22 2016, a “senior Trump campaign official” was “directed” to contact Mr Stone about any other information WikiLeaks that could damage Hillary Clinton’s campaign.
“Stone thereafter told the Trump campaign about potential future releases of damaging material by [WikiLeaks],” the indictment claimed.
Mr Stone is due to make an initial appearance on Friday morning in federal court in Fort Lauderdale.
