Iranian nuclear scientist Shahram Amiri, who surfaced in Washington more than a year after Tehran claimed he was abducted by US spies, is on his way home, the foreign ministry said on Wednesday.

Before leaving Washington where he took refuge on Tuesday in Iran's Interests Section office, Amiri told Iranian Press TV channel he will reveal the details of his "ordeal" to local media on reaching Tehran.

"A few moments ago, Shahram Amiri left US soil ... for Iran following efforts taken by the Islamic Republic of Iran and the effective cooperation of the Pakistani embassy in Washington," foreign ministry spokesman Ramin Mehmanparast was quoted as saying by ISNA news agency.

He said Amiri was first headed to a "third country" from where he would continue to Iran, adding that the head of the Iran Interests Section in Washington, Mostafa Rahmani, saw him off.

Repeating accusation that Amiri was kidnapped by US agents, Mehmanparast said Iran would continue to pursue his case "legally and diplomatically."

Amiri disappeared from Saudi Arabia in May 2009, sparking accusations by Iranian officials that he was kidnapped by the Central Intelligence Agency.

Washington denied the allegations amid speculation and US media reports that he had defected to the United States.

US Secretary of State Hillary Clinton told reporters on Tuesday there was nothing stopping Amiri returning to Iran.

"He's free to go. He was free to come. These decisions are his alone to make," she said.

But in a twist to the bizarre saga which has baffled the media for several months, US officials confirmed on Tuesday that they had been in touch with Amiri since his arrival in the United States.

US State Department spokesman Philip Crowley said Amiri "has been here for some time, I'm not going to specify for how long, but he has chosen to return."

"The United States government has maintained contact with him," he told reporters.

Crowley refused to comment on whether Amiri had provided the United States with intelligence but said US officials had been in contact with him.

US television network ABC first reported Amiri's defection in March and quoted officials saying it was an "intelligence coup" in efforts to undermine Iran's nuclear programme.

Amiri himself has insisted US agents had kidnapped him.

"My abduction is a detailed story," he told Press TV channel in an interview given in Washington soon after he reached the Interests Section.

Amiri said he will reveal the details of his abduction to the Iranian media on reaching home.

"When I am hopefully in my dear country Iran, I can speak to the media and my own people with ease of mind and tell them about my ordeal over the past 14 months, incidents that have been a mystery to many," he said in remarks posted on the channel's English website.

"In Iran, I will thoroughly clarify the allegations made by foreign media and the US government which, in fact, have targeted my reputation."

Amiri's saga has been tied to growing international pressure over Tehran's controversial nuclear programme, which Iran says is for peaceful purpose, but many nations fear masks a weapons drive.

In June several Internet videos emerged featuring a man purporting to be Amiri who claimed to have escaped from US agents in Virginia.

Prior to his disappearance, Amiri worked in Tehran's Malek Ashtar University of Technology, which is believed to be close to Iran's elite Revolutionary Guards.

earlier related report
'Abducted' Iran scientist surfaces in US
Washington (AFP) July 13, 2010 - An Iranian scientist Tehran claims was abducted by US spies surfaced Tuesday in Washington, where officials confirmed he had been living "for some time" but said he was was free to leave.

It was the latest twist in a bizarre saga tied to international pressure over Tehran's controversial nuclear program, which Iran says is for peaceful purpose, but many nations fear masks a weapons drive.

Iran says US agents kidnapped Shahram Amiri after he arrived in Saudi Arabia for a pilgrimage last year, but speculation has mounted that he defected and was working with the Central Intelligence Agency.

US officials denied kidnapping the Iranian, even as several Internet videos emerged in June featuring a man purporting to be Amiri who claimed to have escaped from US agents in Virginia.

On Tuesday, Amiri was holed up at Iran's consular mission in a non-descript office building in Washington, and US officials confirmed for the first time that he was in the United States.

"He's free to go. He was free to come. These decisions are his alone to make," Secretary of State Hillary Clinton told reporters.

She contrasted the case to that of three young American hikers, who have been held in Iran for nearly a year after allegedly straying into the country during a hiking trip. She renewed calls for their release.

White House spokesman Robert Gibbs declined to detail how the Iranian scientist had come to the United States, or what he had done while he was in the country.

"He's here and he's free to go. We don't hold him and therefore he's not part of any exchange," he said, echoing Clinton's remarks. "Iran continues to hold three hikers and we believe they should be released."

State Department spokesman Philip Crowley said Amiri had planned to return Monday to Iran but could not complete all the arrangements in time to transit through a third country.

"He's been here for some time, I'm not going to specify for how long, but he has chosen to return," Crowley said.

Crowley refused to comment on whether Amiri had provided the United States with intelligence but said US officials had been in contact with him.

An Iran watcher who has contacts with the US administration told AFP that Amiri, who is in his early 30s, had defected and moved in the Sun Belt city of Tuscon, Arizona, but that his family in Iran apparently came under pressure.

"He wasn't a real big fish. He oversold himself. He was debriefed and then allowed to go live in Tuscon," said the academic, who requested anonymity to discuss sensitive information.

"He had illusions of what life as a defector might be like. But he realized that the future didn't look bright as he doesn't know the language and was all alone."

US television network ABC first reported Amiri's defection in March and quoted officials saying it was an "intelligence coup" in efforts to undermine Iran's nuclear program.

Amiri told Iranian media he had asked "for a quick return to Tehran." He said he was under intense "psychological pressure" and was constantly watched by "armed people."

"After the release of my interview on the Internet and the disgrace for the American government over this abduction, they wanted to quietly return me to Iran by some country's airline, so that while denying the whole thing they can put a cap on the abduction," he told Iranian state television.

"But in the end they couldn't. Since the day of the release of my remarks on the Internet, the Americans have seen themselves as losers in this saga," he said.

"I am not free and I'm not allowed to contact my family. If something happens and I do not return home alive, the US government will be responsible," the man said, insisting he had not "betrayed" Iran.

There was no sign of the mysterious scientist at the Iranian interests section in the United States, which is under the auspices of the Pakistani embassy in the absence of diplomatic relations between Washington and Tehran.

Secret Service agents waited outside in squad cars with engines running and patrolled a park adjacent to the mission, which lies in a little-marked office building near the upscale Georgetown area.

Officials inside the mission confirmed that Amiri was inside but politely tried to shoo away waiting reporters, who cast a careful eye on each vehicle with tinted windows leaving the building's underground garage.

Prior to his disappearance, Amiri worked in Tehran's Malek Ashtar University of Technology, which is believed to be close to Iran's elite Revolutionary Guards.

On a visit to Madrid, Iranian Foreign Minister Manouchehr Mottaki called for the United States to allow Amiri's immediate return.

"We hope that, without any obstacle, he can return to his country, that they do not create any obstacle for his return to his homeland," he told a news conference.