Exclusive: Iranian Nuke Scientist Is En Route to Iran

July 14, 2010— -- The CIA has lost one of its most valued former spies.

Iranian nuclear scientist Shahram Amiri, who defected to the US, is now on his way back home to Tehran after a very messy and public re-defection.

ABC News obtained exclusive photos of Amiri leaving Washington's Dulles International Airport late Tuesday night on a commercial flight to Doha, Qatar, en route to Iran.

Amiri was escorted directly to the jetway entrance by a security officer. He was flanked by what appeared to be a U.S. official and a representative from the Pakistani Embassy in Washington._He boarded the Qatar Airways flight ahead of the other passengers, and spoke only to his companions.

After more than a year in the US, Amiri claimed he had never really defected. In a series of videos released on the internet, he insisted that he had been kidnapped, drugged and tortured by the CIA.

The US flatly denies that it ever held Amiri against his will.

"Let me say that Mr. Amiri has been in the United States of his own free will," said Secretary of State Hillary Clinton. "And he is free to go."

Clinton said that Amiri was actually scheduled to travel to Iran on Monday "but was unable to make all the of the necessary arrangements to reach Iran through transit countries."

U.S. officials tell ABC News that Amiri defected in the spring of 2009 after working for several years for the CIA while still inside the Iranian nuclear program.

But officials say that after Amiri was re-located to Tucson, Arizona he began to have second thoughts.

In a battle of videos posted on YouTube, first by the Iranians and then the CIA, Amiri changed his story three times.

First, he told Iranian TV via computer phone he had been kidnapped.

Then, in a CIA-produced video, Amiri said he was happy to be in the US.

Later, he again claimed he was trying to elude US agents so he could be reunited with his wife and son in Iran.

"In case anything happens to me or if I do not make it back home safely, the responsibility will solely rest on the officials of the United States," Amiri said in one of the videos.

CLICK HERE and HERE TO SEE AMIRI'S MOST RECENT VIDEOS IN ENGLISH

"This happens all the time," said Bob Baer, a former CIA officer who worked in the Middle East. "Defectors come up with a good idea to make a lot of money, and then once the boredom sets in and the loneliness, they want to get back in touch with the family. They realize it was a huge mistake."