Sen. Diane Feinstein released a letter that she received from Stone’s lawyer, in which he said that the requests for documents were too broad, far-reaching and wide-ranging.
Lawyer Grant Smith pointed out that his client already testified before the House Intelligence Committee, and was denied his request for a public testimony by a committee that preferred to interview him behind closed doors.
A transcript of that session may soon be released.
“On the advice of counsel, Mr. Stone will not produce the documents requested by you in your capacity as Ranking Minority Member of the Judiciary Committee,” Smith wrote in the letter.
He concluded the letter by saying Stone’s decision to invoke the Fifth Amendment “must be understood by all to be the assertion of a Constitutional right by an innocent citizen who denounces secrecy.”
Stone is under scrutiny in special counsel Robert Mueller’s investigation into Russian interference in the 2016 presidential campaign, as Mueller looks to ascertain whether Stone had advance knowledge of WikiLeaks’ plans to release a trove of hacked emails from the Clinton campaign.
The 66-year-old Stone has denied having prior knowledge of WikiLeaks’ plans. He has not been charged.
WATCH: Roger Stone associate Jerome Corsi says he is in plea negotiations with Robert Mueller’s office
Stone has been an outspoken critic of Mueller’s, and said in September 2017 that Trump should fire the special counsel.
The longtime Republican strategist said he would “never testify against Trump,” a stance that earned him praise from President Donald Trump in a tweet on Monday.
“Nice to know that some people still have ‘guts!'” Trump tweeted.
WATCH: Roger Stone says Trump should fire Robert Mueller
A federal grand jury has heard testimony for months from Stone associates and offered a plea deal to one friend, Jerome Corsi, that would have required him to admit to lying to investigators about a conversation he had with Stone about WikiLeaks.
Corsi has rejected that offer.
— With files from the Associate Press