The United States received useful information from Iranian nuclear scientist Shahram Amiri who decided to return to Iran this week, a U.S. official said on Wednesday.
"We got useful information from him, and the Iranians got Amiri. Ask yourself who got the better deal," the official said on condition of anonymity.
Amiri, who Tehran claims was abducted by the United States, took refuge on Tuesday at the Pakistani embassy in Washington and asked to return to his homeland, U.S. and Iranian officials said.
Amiri was on Wednesday heading for an official welcome in Iran in a murky tale that goes to the heart of U.S.-Iranian mistrust.
Iran has accused the CIA of kidnapping Amiri, who worked for Iran's Atomic Energy Organization, a year ago in Saudi Arabia. Washington denied abducting Amiri and said he had been free to leave the United States but did not say why he was there.
Iran is locked in a dispute with the United States and its allies over Tehran's nuclear program, which the West says is designed to produce nuclear weapons and Iranian officials say aims to generate power.
Three months after Amiri's disappearance, Iran disclosed the existence of a hitherto-secret uranium enrichment site, near the Shi'ite holy city of Qom.
Contradicting the American account that Amiri had been in the United States of his own free will, Amiri on Wednesday painted a dramatic picture of a cloak-and-dagger operation to abduct him.
"While I was on the pilgrimage in Saudi Arabia, a car offered me a lift...a gun was pointed at me as soon as I got in the car," Amiri told state television. "Then I was drugged ... I was transferred to America by a military plane."
Iran's Foreign Ministry said Amiri, who surfaced at the Iranian interests section of the Pakistani embassy in Washington on Monday, was now on his way back to Iran.
"With the effective cooperation of Pakistan's embassy in Washington, a few minutes ago Shahram Amiri left American soil and is heading back to Iran via a third country," spokesman Ramin Mehmanparast said on television.
Another ministry official, Hasan Qashqavi, said Amiri was travelling via Qatar. "He will be welcomed by officials at Tehran's Imam Khomeini International Airport on Thursday," he said, according to state TV.
Amiri is provisionally expected to land at roughly 2300 GMT (Wednesday).
Iran said the Foreign Ministry would pursue Amiri's case through legal and diplomatic channels to nail down what part the U.S. government played in the saga.
The State Department said the United States did not kidnap Amiri, but it has not addressed whether another country might have abducted him and turned him over.
A man identifying himself as Amiri has variously said in recent videos that he was kidnapped and tortured; that he was studying in the United States; and that he had fled U.S. agents and wanted human rights groups to help him return to Iran.
Amiri was quoted by Iranian state TV on Tuesday as saying: "My kidnapping was a disgraceful act for America."
Intelligence about the Iranian nuclear program is at a premium for the United States, which fears that a nuclear-armed Iran would threaten its close ally, Israel, as well as oil supplies from the Gulf, and friendly nations in Europe.
Asked why Amiri was going back, a U.S. official, who spoke on condition of anonymity, said: "He may well be feeling some pressure from back home. The
Iranians aren't beyond using family to influence people. That could be one explanation for his contradictory messages."
He also sought to cast doubt on Amiri's account, saying the fact that he had been free to make videos and to leave undercut his claim of coercion.
Amiri said he would reveal more details on his arrival in Iran. "I have a very long and detailed story ... I have explained some key parts in the footage broadcast in the past."