Justice Department special counsel Robert Mueller's office wants to interview the man who has been described as the link between WikiLeaks and Donald Trump's inner circle.

Former radio host Randy Credico — who denies serving as that link but says he has served as a go-between at other times to WikiLeaks — told NPR that a prosecutor working for Mueller had asked him for a voluntary meeting.

Credico said he declined. The special counsel's office declined to comment.

Mueller's office didn't give a reason for the outreach but has evidently been ratcheting up pressure on the Trump campaign's end of the chain, specifically Trump's longtime confidant Roger Stone.

"I am sure [the request] is connected to Stone ... or our exchanges over two-plus years," Credico told NPR.

Credico said that he has received legal threats from Stone and that Stone has accused him of being a Mueller informant. Credico is keen to avoid that impression.

"With all due respect to the special prosecutor, who I certainly do not want to irritate, I will do an interview if I get a subpoena," Credico said. "A voluntary interview would prompt Stone and his clan of nuts to smear me by labeling me a rat, an informant."

Reached for this story, Stone declined to comment. But in the past he has said that Credico is a "liar" whose word cannot be trusted.

The two have a long and tumultuous history. Credico, who is also a comedian, was once allied to the Nixon-loving, Trump-boosting Stone back in the 2000s, when they teamed up in a bid to loosen New York state's drug laws.

Stone is the longtime Republican operative who was a confidant of Trump's through 2016 and appeared, during the election, to know before the fact that something was going to happen to Hillary Clinton's campaign chairman, John Podesta. Podesta's emails had been stolen by Russian government hackers and were released via WikiLeaks.

Stone told congressional investigators that Credico connected him with WikiLeaks and its founder, Julian Assange. But Stone denies knowing anything about the Russian government's active measures campaign against the United States.

Credico has told NPR that Stone asked for a connection with Assange, but Credico says he didn't make the introduction.

Mueller's investigators are very likely trying to establish precisely what did take place in 2016 and since. They have interviewed at least five of Stone's associates, though not yet Stone himself.

Even though the former radio host denies he brokered a contact between Stone and WikiLeaks, Credico says he does have a relationship with WikiLeaks and Assange. Credico has met Assange and interviewed him on a number of occasions.

And Credico told NPR he offered to serve as a go-between to Assange for the House intelligence committee.

Assange has stayed inside the Ecuadorean Embassy in London for six years, seeking to avoid arrest. Initially he sought asylum there to avoid being detained in connection with rape allegations in Sweden. Although that case was dropped last year, Assange has remained in the embassy.

One open question is whether if Assange left the diplomatic protection afforded by the embassy, he might be arrested and charged with other crimes — for example, by Mueller or another American prosecutor in connection with the various disclosures WikiLeaks has made.

American intelligence officials consider WikiLeaks a "hostile intelligence service."

