A lawyer for Bryan Pagliano, the former State Department computer staffer who set up Hillary Clinton’s private email server, recently informed Congress that he will not testify before Senate committees investigating Clinton’s email setup.

The Associated Press obtained a letter sent by Mark MacDougall, Pagliano’s lawyer, on March 11 indicating that his client would "respectfully decline" the offers from the Senate Judiciary Committee and the Senate Homeland Security Committee to testify before congressional lawmakers.

Pagliano declined to testify before the committees even after he was granted immunity by the Justice Department and has been cooperating with the FBI in its investigation into Clinton’s email setup.

The former State Department IT staffer asserted his Fifth Amendment right in September in response to a subpoena from the House Select Committee on Benghazi to testify before congressional lawmakers. The Senate Judiciary and Homeland Security Committees had also reached out to Pagliano then to testify.

After reports in March that Pagliano had accepted the immunity grant, the leaders of the Judiciary and Homeland Security Committees again reached out to the ex-Clinton aide asking him to testify. They informed Pagliano that the immunity grant should alleviate the concerns he had about doing so.

Pagliano’s attorney wrote in the letter that the former staffer had "not waived his rights under the Fifth Amendment as a matter of fact or law." The letter did not contain details about the immunity granted to Pagliano.

"With all appropriate respect, whether and when a citizen may assert a Fifth Amendment a constitutional right is not up to your legal staff," MacDougall wrote. "Whatever agreement Mr. Pagliano may have reached with the Department of Justice in no way constitutes a waiver of his Fifth Amendment rights."

Pagliano, who worked on Clinton’s failed 2008 presidential campaign, set up her personal server in her home in Chappaqua, New York, in 2009. He worked in the State Department’s information technology department during Clinton’s tenure as secretary of state.

Clinton’s server has been found to hold more than 2,000 emails containing information that is now classified, though none of the messages were marked classified when they originated on her email. Clinton has maintained that she never sent nor received information marked classified on her personal email.

The FBI is reportedly looking into whether classified information was mishandled, though Clinton has repeatedly described the probe as a "security review." FBI agents may move to question former Clinton aides and even the former secretary of state herself as they complete the investigation, reports have indicated.