Iran said yesterday it would use legal channels to secure the release of its nuclear scientist Shahram Amiri, who in a video clip screened on Iranian television channels said he was kidnapped by U.S. agents. A second video posted on You-Tube said he was happy to be in the United States.

Ramin Mehmanparast, an Iranian Foreign Ministry spokesman, said the first video confirmed Tehran's charges Mr. Amiri had been abducted by U.S. and Saudi intelligence services.

But Washington denied the accusation.

"Have we kidnapped an Iranian scientist? The answer is no," Philip Crowley, a State Department spokesman, said in Washington.

In the clip aired in Iran, the man identified as Mr. Amiri said he was in Tucson, Ariz., and had been kidnapped by U.S. agents en route to Mecca in Saudi Arabia in June 2009.

His abduction was intended to pressure Tehran, he added.

The television said Iranian intelligence services had obtained the film "by special methods," without elaborating.

Tehran summoned the ambassador of Switzerland, which represents Washington's interests in Iran in the absence of a U.S. embassy, the official IRNA news agency reported.

The man in the Iranian footage is filmed in a closed

room, apparently with the use of a webcam, and wearing headphones.

"Their aim is to make me give an interview to one of the major U.S. television networks to say I'm an important figure in the Iranian nuclear program and that I have asked for asylum in the United States," he said.

"I have to say that I have important documents in my possession as well as a computer with secret information."

In March, ABC news reported Mr. Amiri, a nuclear physicist in his early 30s, had defected and was working with the Central Intelligence Agency.

Yesterday, the network said a second video of Mr. Amiri had been posted on YouTube.

"I am free here, and I assure everyone I am safe," he said, according to a translation by the BBC.