Hillary Clinton, the frontrunner for the Democratic presidential nomination, has been engulfed in fresh controversy over her tenure as US secretary of state after revelations that she relied solely on a personal email account to do government business.
The news came amid reports that Mrs Clinton was considering plans to launch her bid for the presidency as early as April and was quickly seized on by Jeb Bush, who has emerged as the leading presidential contender among moderate Republicans.
Mrs Clinton’s camp launched a strong defence of her actions, arguing that she had broken no rules and previous secretaries of state had also used personal email accounts for work.