US Vice President Mike Pence used a private email as governor of Indiana to discuss sensitive matters - and the account was hacked - according to reports.

The Indianapolis Star said it had seen emails that showed Donald Trump’s deputy had used his personal AOL account to communicate with advisers on topics ranging from security gates at the governor's residence to the state's response to terrorism attacks.

In one email, Indiana’s top security adviser messaged Mr Pence with an update from the FBI regarding the arrests of several men being held on terror charges.

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The newspaper said the Vice President’s account was hacked last summer. Mr Pence served as governor from January 2013 until January this year.

But the report did not make clear whether any sensitive information was compromised during the hack.

Indiana law does not prohibit public officials from using personal email accounts, the Star reported.

However the claims, if proven to be true, will come as a huge embarrassment for the Republican party, and Mr Trump’s inner circle in particular, who strongly criticised Hillary Clinton for using a private email while she was secretary of state.

A statement issued by the Vice President’s office said: "Similar to previous governors, during his time as Governor of Indiana, Mike Pence maintained a state email account and a personal email account.

“As Governor, Mr Pence fully complied with Indiana law regarding email use and retention.

“Government emails involving his state and personal accounts are being archived by the state consistent with Indiana law, and are being managed according to Indiana’s Access to Public Records Act.”

An unspecified number of emails were not released to the paper because they were deemed to be confidential.

Mr Pence called a decision last summer by the FBI not to investigate Ms Clinton’s use of private emails “troubling”.