Amir Mirzai Hekmati was "sentenced to death for co-operating with a hostile nation, membership of the CIA and trying to implicate Iran in terrorism," semi-official Fars news agency said.

The 28-year-old's trial last month heard he had confessed to the charges.

But Mr Hekmati's US-based family say he was in Iran visiting his grandmothers.

The US has said he has been falsely accused and has called for his release.

Mr Hekmati was accused by Iran of receiving training at US bases in Afghanistan and Iraq before being sent to Iran.

During his trial in December, prosecutors cited what they said was a confession Mr Hekmati had made on state TV some days earlier, in which he had admitted trying to infiltrate Iran's intelligence services for the CIA.

According to Fars, he told the court he did have links to the CIA, but had never intended to harm Iran.

"I was deceived by the CIA... Although I was appointed to break into Iran's intelligence systems and act as a new source for the CIA, I had no intention of undermining the country," Fars quoted him as saying.

Mr Hekmati's family, who live in Arizona, say the charges against him are fabricated and that he was in Iran to visit his grandmothers.

His father, Ali Hekmati, said his son joined the US military in 2001 and served in the Marines, where he was an Arabic translator.

bbc.com