'Abducted' Iranian surfaces in America

Iran's state TV said Shahram Amiri, whom it claims was abducted by America, had demanded an "immediate return" to Iran.

Pakistan's foreign ministry, which represents Iran diplomatically in the US, said the scientist arrived on Monday and had been with them since.

"We understand from Dr Rahmani that they are making arrangements for his repatriation to Iran," he said.

Mr Amiri disappeared while on a pilgrimage to Saudi Arabia in June 2009. Iran has repeatedly claimed the US abducted him – which it denies.

Before he disappeared, Mr Amiri worked at Tehran's Malek Ashtar University, an institution closely connected to the country's powerful Revolutionary Guard.

US media reported in March that Mr Amiri defected to the US and was assisting the CIA in efforts to undermine Iran's nuclear programme.

Iran's state TV has periodically showed purported videos of Mr Amiri claiming abduction and torture by the US. One of the videos, aired in June, showed a man wearing headphones and speaking through what appeared to be a webcam, saying he was abducted while on a pilgrimage to Medina, injected with a tranquilliser and taken to the US.

Iran has previously hinted it would trade three American prisoners it has held since last July for a number of Iranians allegedly detained by the US, including Mr Amiri.

Last month the United Nations imposed a fourth round of sanctions on Tehran over its refusal to curtail its nuclear programme.