The FBI has interviewed presumptive Democratic presidential nominee Hillary Clinton about her use of a private email server while serving as secretary of state.

�Secretary Clinton gave a voluntary interview this morning (Saturday) about her email arrangements while she was secretary,� Clinton spokesman Nick Merrill said in a statement.

�She is pleased to have had the opportunity to assist the Department of Justice in bringing this review to a conclusion. Out of respect for the investigative process, she will not comment further on her interview,� Merrill added.

Her interview with the FBI, which lasted three and a half hours in Washington, could intensify anxiety among Democrats that she might be indicted before the November elections.

�Timing of FBI interview, between primaries and convention, probably good timing for @HillaryClinton,� tweeted David Axelrod, a former senior adviser to President Barack Obama who worked as the chief strategist for his two presidential campaigns. �Best to get it behind her.�

Clinton is expected to be formally nominated as the party's presidential candidate during the Democratic National Convention in the following weeks.

However, her use of a personal email to conduct State Department business has negatively affected her campaign, with her Republican rival Donald Trump saying that she should face �criminal charges.�

�It is impossible for the FBI not to recommend criminal charges against Hillary Clinton. What she did was wrong! What Bill did was stupid!� Trump tweeted.

Trump was referring to a private meeting between Attorney General Loretta Lynch and former President Bill Clinton ahead of his wife�s interview with the FBI.

On Friday, Lynch acknowledged that her meeting with Clinton�s husband was a mistake that had cast a shadow over the email investigation.

Clinton has already apologized for using a private email account and server from 2009 to 2013, but her critics argue the former secretary of state�s violations of regulatory protocol amount to a prosecutable crime.

FBI investigators have interviewed several of Clinton aides, including her deputy chief of staff, Huma Abedin, and former chief of staff Cheryl Mills.

By Press TV