The intermediary between longtime Trump confidant Roger Stone and WikiLeaks founder Julian Assange has notified members of the Senate Intelligence Committee that he is planning to plead the Fifth Amendment so he would not self-incriminate himself by answering questions related to the committee’s probe on Russian interference in the 2016 election.

New York radio personality Randy Credico’s lawyer notified the committee on Monday that Credico planned to plead the Fifth Amendment when he appears before the panel on Friday, according to a Politico report. The panel had previously subpoenaed Credico.

“Should the committee require a personal appearance by Mr. Credico to orally assert his rights, please let us know,” Credico’s lawyer Martin Stolar wrote the Senate Intelligence Committee.

Credico testified last month before a grand jury as part of special counsel Robert Mueller’s Russia investigation, which is examining Russian interference in the 2016 election and whether the Trump campaign colluded with the Kremlin.

However, Credico reportedly invoked the Fifth Amendment last year after the House Intelligence Committee issued him a subpoena.

Stone, who has claimed that Credico was his intermediary between WikiLeaks and Assange, attracted scrutiny from investigators after he appeared to anticipate the publication of stolen documents on the WikiLeaks website, saying in 2016 on Twitter that Hillary Clinton campaign chairman John Podesta's "time in the barrel" would soon occur.

Stone has denied ever having any early-access knowledge from WikiLeaks about the release of Podesta's emails. Rather, he claimed the statement was based on his own investigations of Podesta and his brother Tony, noting that his tweet in fact said "the Podesta's time in the barrel."

WikiLeaks is well-known for publishing leaked secrets on its website, such as releasing stolen emails from Democratic officials during the 2016 campaign as well as documents on CIA hacking tools.

The U.S. intelligence community concluded in a 2017 assessment that WikiLeaks was used by Russia intelligence to release information as part of an effort to elect Trump. WikiLeaks denies this assertion.