Hillary Clinton did not comply with government policies for avoiding cybersecurity risks while serving as Secretary of State, an internal State Department audit has found.
The inspector general’s report, a copy of which was obtained by the AP news agency, was critical of Mrs Clinton’s use of a private email server – a controversy that has hung over her presidential campaign.
The audit’s findings cited “longstanding, systemic weaknesses” related to the State Department’s communications dating back to previous heads of state.
But Mrs Clinton’s failures were more serious, the report stated.
“By Secretary Clinton’s tenure, the department’s guidance was considerably more detailed and more sophisticated,” the inspector general’s 78-page analysis concluded, according to AP.
“Secretary Clinton’s cybersecurity practices accordingly must be evaluated in light of these more comprehensive directives.”
The report said the Democratic front runner disregarded guidelines and never sought approval to use mobile devices to conduct official business on her personal email account and private server.
The inspector general also criticised Mrs Clinton for failing to turn over records promptly and noted that she declined to be interviewed as part of the audit.
Mrs Clinton, who was Secretary of State between 2009 and 2013, has said her private email server did not break any rules and has insisted she will be vindicated.
She has not commented on the inspector general’s report, which was released to US lawmakers on Wednesday.
Separately from the State Department audit, FBI agents have been probing whether Mrs Clinton’s use of the private server violated federal laws in regard to classified documents.
Meanwhile, a Romanian hacker known as Guccifer, who claimed he infiltrated Mrs Clinton’s email server, pleaded guilty in US court on Wednesday to charges of identity theft and other offences.
Marcel Lazar, 44, was best known for alleged hacks into accounts held by the Bush family that revealed private family photos and paintings.
He made headlines again earlier this month after making the unsubstantiated claim that he hacked Mrs Clinton’s server.