Hillary Clinton: US State Department review into personal email controversy could take months

A review by the US State Department into the use of a personal email account by Hillary Clinton while she had the top diplomatic job could take months and will investigate whether she violated government policy.

It was revealed last week that Hillary Clinton used a private email account, rather than a government account, during her time at the State Department.

Her actions have opened a potential legal quagmire, with accusations she violated federal record-keeping rules.

Department spokeswoman Marie Harf refused to speculate on the possible breach of policy or who would determine whether that was the case.

"I'm just not going to speculate on those kinds of hypotheticals," she said.

"I'm not ruling anything in or out. I think nothing about this issue is simple, as we've all learned in the past four days."

But former New York governor George Pataki echoed other Republicans in accusing her of double standards.

"You know, we just see hacking as a major cyber crime, as a major, major issue," he said.

"The secretary of state is setting up her own account that could be hacked by North Korea, by Iran or others."

Last month there were reports the Clinton Foundation, set up by the former president and his wife, accepted millions of dollars from foreign governments during her time at the State Department.

The Washington Post reported most of the donations were permitted under an agreement with the Obama administration, but at least one may have breached that agreement.

Some suggested the email and donation controversies were damaging because they undermined confidence in the Democrats' strongest candidate, as anticipation mounts that she will soon announce her run for the presidency.