The US State Department has reopened its investigation into Hillary Clinton’s private email servers – a veritable thorn in the side her campaign – to determine whether she and top aides mishandled classified information.

According to the Associated Press, the internal investigation will not result in criminal charges. Many of Ms Clinton’s top aides could have their security clearances revoked, which would all but dissolve their chances of being a part of the national security team should the former Secretary of State win the presidency.

“We will aim to be as expeditious as possible, but we will not put artificial deadlines on the process,” said State Department spokesperson Jack Kirby. “Our goal will be to be as transparent as possible about our results, while complying with our various legal obligations.”

The State Department had launched their internal investigation in January, but suspended it so as not to interfere with the Federal Bureau of Investigation’s probe.

The probe by the department will focus on 22 emails found on Ms Clinton’s emails that were considered to be “top secret”.

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Mr Kirby would not identify the top aides under investigation, but the AP said the ones most likely to face scrutiny are Jake Sullivan, Cheryl Mills, and Huma Abedin.

Attorney General Loretta Lynch official closed the Justice Department’s investigation into the Clinton emails without filing criminal charges against the presumptive Democratic nominee – per FBI director James Comey’s recommendation a day prior.

“Late this afternoon, I met with FBI Director James Comey and career prosecutors and agents who conducted the investigation of Secretary Hillary Clinton’s use of a personal email system during her time as Secretary of State,” Ms Lynch said in a statement. “I received and accepted their unanimous recommendation that the thorough, year-long investigation be closed and that no charges be brought against any individuals within the scope of the investigation.”

Although the FBI found no reason to charge Ms Clinton, Mr Comey still found her handling of the emails to be “extremely careless”.

“There is evidence to support a conclusion that any reasonable person in Secretary Clinton’s position, or in the position of those government employees with whom she was corresponding about these matters, should have known that an unclassified system was no place for that conversation,” he said.