Iranian scientist claims torture by US

Shahram Amiri was embraced by his family – including his tearful seven-year-old son – after arriving in Tehran in the latest spectacle of a puzzling series of events in which Iran and Washington have given starkly different accounts.

Iran has portrayed the return of Mr Amiri as a blow to American intelligence services that were desperate for inside information on Iran's nuclear programme.

Reports in the US have said he was a willing defector who changed his mind and decided to go home.

Iran sought maximum propaganda value – allowing journalists to cover Mr Amiri's return and having a top envoy from Iran's Foreign Ministry on hand to greet him.

Washington described the 32-year-old Mr Amiri as someone who reached out to US officials but offered few other details.

Speaking to journalists after a flight via Qatar, Mr Amiri repeated his earlier claims that he was snatched while on a pilgrimage last year in the Saudi holy city of Medina and carried off to the US.

He claimed he was under intense pressures during the first few months after his alleged kidnapping.

"I was under the harshest mental and physical torture," he said at Tehran's international airport, with his son sitting on his lap.

He also alleged that Israeli agents were present during the interrogations and that CIA officers offered him $50m to remain in America.

He gave no further details to back up the claims or shed any new light on his time in the US, but promised to reveal more later.

"I have some documents proving that I've not been free in the United States and have always been under the control of armed agents of US intelligence services," he told reporters.

He sought to play down his role in Iran's nuclear programme, which Washington and allies fear could be used to create atomic weapons. Iran said it only seeks energy-producing reactors.

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

"I am a simple researcher who was working in the university," he said. "I'm not involved in any confidential jobs. I had no classified information."

His case was often raised by Iranian officials in the past year but Washington offered no public response. It took a higher profile after Iranian authorities decided to pursue charges against three American hikers captured in July 2009 on the Iran-Iraq border.

Iran's deputy foreign minister, Hassan Qashqavi, said there would be "no link" between Mr Amiri's return and the case of the three Americans.

Last month Iranian state TV aired a video in which Mr Amiri claimed he was taken captive by US and Saudi "kidnap teams".