WASHINGTON: The FBI interviewed Hillary Clinton on Saturday about her use of personal email while serving as secretary of state, an issue that has dogged her campaign to become America’s first female President. Questions over Clinton’s use of a private account and homebrew server during her time as America’s top diplomat have fueled voter concerns that she is not trustworthy. An aide said the interview at FBI headquarters in Washington lasted about 3.5 hours, following previous such interviews with Clinton aides, including close confidante Huma Abedin. It comes about three weeks before the Democratic National Convention is set to crown Clinton as the party’s official White House nominee. The interview signals that the FBI’s protracted criminal investigation could be entering its final phase, with a long-awaited decision nearing. Clinton has apologized for exclusively using a private email account and her own server during her time as secretary of state from 2009 to 2013. Opponents argue that this breached rules about protecting classified documents from cyber attack and may have amounted to a crime.