“Secretary Clinton gave a voluntary interview this morning about her email arrangement while she was Secretary. She is pleased to have had the opportunity to assist the Department of Justice in bringing this review to a conclusion,” Clinton spokesman Nick Merrill said after a three and a half hour interview.

“Out of respect for the investigative process, Clinton will not comment further on her interview,” Merrill added.

Clinton was interviewed at FBI Headquarters in Washington DC.

Clinton was up for questioning after evidence emerged in March 2015 that, while performing the duties of Secretary of State, she had been using a personal, unsecured email server installed in her New York home. The FBI is investigating whether anyone in Clinton's operation mishandled classified information due to it not being properly protected at the time. Several of Clinton's staff members have already been interrogated over the case, as well as her top aide Huma Abedin.

Clinton released some 30,000 emails from her time as Secretary of State, with 2,028 of them containing confidential information. The use of an external, personal server violated the Federal Records Act which sets out “recordkeeping requirements,” but the investigation is yet to determine whether the presidential candidate should be indicted on criminal charges.

Despite criminal prosecution being unlikely, the ongoing investigation poses a major risk for Democrats only four weeks away from formally nominating the party's presidential candidate, RT reported.

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