A missing Iranian nuclear scientist dramatically turned up at the Iranian interests section of Pakistan's embassy in Washington, and was quoted as saying he was kidnapped by US agents in a “disgraceful act”. But a US official, who declined to be named, said Shahram Amiri had been visiting the United States and had decided “to return to Iran of his own free will”. Tehran has repeatedly accused the CIA of abducting Amiri, who worked for Iran's Atomic Energy Organisation, but ABC news had reported he defected and was helping the agency. Washington denied he was spirited away for nuclear secrets. “My kidnapping was a disgraceful act for America .I was under enormous psychological pressure and supervision of armed agents in the past 14 months,” Amiri, who is in his thirties, was quoted as saying in a phone interview with Iran's state TV. Iran is locked in a dispute with the United States and its allies over Tehran's nuclear development programme that the West says is designed to produce nuclear weapons and which Iranian officials say aims to generate power. The Amiri case provoked speculation about whether he had valuable intelligence about the Iranian nuclear programme that the Americans wanted.”Mr. Amiri has been in the United States of his own free will and has decided to return to Iran of his own free will,” the US official said, adding Amiri is awaiting documents from a third country through which he plans to travel to Iran. Amiri's surfacing comes after a Cold War-style spy swap which took place in Vienna on Friday when 10 people charged in the United States with being Russian agents were exchanged for four held in Russia on charges of spying for the West. “Amiri has been escorted by American forces to Iran's interests section in Washington,” Iran's PressTV said.