Hillary Clinton's campaign team have questioned the timing of the Federal Bureau of Investigation's probe into her personal email use.
FBI head, James Comey, is under pressure to reveal what the bureau knows and explain what Mrs Clinton has allegedly done wrong.
The White House has dampened suggestions that the FBI's head is trying to influence the outcome of the US presidential election by revealing details of a new investigation into Hillary Clinton's emails.
A spokesman said that president Barack Obama did not believe that the security service's director James Comey was secretly trying to benefit Donald Trump by announcing the FBI were again examining his rival Clinton's emails.
It comes after Mr Comey made the highly unusual decision to inform congress that the agency was again reviewing the Democratic nominee's email use in the run-up to the election.
A White House spokesman today said that Mr Obama believed it was important for the FBI to follow historical norms and traditions, but he believed that Mr Comey was a man of "integrity and good character".
The emails were found on a laptop seized from Clinton's aide's estranged husband, ex-congressman Anthony Weiner.
The FBI Director's letter has placed a dark cloud of suspicion over Mrs Clinton, and no one - perhaps not even he himself - knows why.
The presidential candidate has called for the FBI to fully explain the new emails that have come to light.