Reporting from Washington and Beirut — Shahram Amiri sounds like a contented man in one video, nestled in a leather chair, assuring his audience that he is free and safe to continue his education in America.
But, in a second clip, the Iranian scientist warns in stilted phrases that the CIA kidnapped him, brought him to the United States and tortured him with the goal of "proving lies" about Iran's disputed nuclear program.
The two online videos sum up the murky and contradictory narratives at the heart of Amiri's tale, which took a surprising turn Monday when the 32-year-old scientist presented himself at the Iranian consular office in Washington saying he wished to go home.
Iran, locked in a standoff with the United States over its nuclear program, quickly resumed its allegations that the U.S. abducted the former researcher for Iran's Atomic Energy Organization.
U.S. officials contended that Amiri, who disappeared in Saudi Arabia in June 2009, had come to the U.S. of his own free will.
But, with many details still unclear, the story has begun to look like a defection gone wrong that could yield a propaganda windfall for the Islamic Republic.
The affair has at least temporarily shifted the focus away from Iran's nuclear program and revived its decades-old claims that the CIA is secretly meddling in its affairs.
U.S. officials, who had said nothing official on the Amiri case until Tuesday, acknowledged that they had remained in touch with him during his stay in the U.S., suggesting that he had shared his knowledge of the Iranian nuclear program.
They also offered a possible motive for Amiri's abduction claims, saying that Iranian officials may have threatened the family that he left behind.
Amiri's mysterious tale became more confused June 7, when two conflicting videos hit the Internet.
The first, released by Iranian authorities, appeared to show Amiri on a webcam, speaking in Persian and saying that he had been kidnapped by the CIA and Saudi Arabian intelligence agents while on a pilgrimage in the Saudi city of Medina.
In the video, which Amiri said he recorded from Tucson on April 5, he charged that after being kidnapped he was given an injection, and when he woke up he was on a plane to the U.S.
But in a second video released on YouTube the same day, Amiri said he was free and safe in the U.S., working on his PhD.
Amiri said on that video that he had no interest in politics and knew nothing about nuclear weapons programs.
Two other videotapes also apparently produced by Amiri appeared later in June, returning to the original theme that he had been abducted.
The videos raise a host of questions, including whether the CIA mishandled his case in its eagerness to acquire new information about the Iranian nuclear program.
Iran's foreign minister, Manouchehr Mottaki, told reporters in Madrid on Tuesday that Amiri had been kidnapped and demanded that he be allowed to return home "without any obstacle."
Iranian state television said Amiri had been in contact with Iranian news organizations in New York and quoted him as saying that he had been imprisoned and under extreme psychological pressure for more than a year.
Several U.S. officials were scathing Tuesday about Amiri, whom they portrayed as naive and impetuous. His decision to defect, they implied, had been made without thinking through the implications, including the possibility that his family could face reprisals.
But the officials were unwilling to address in detail the U.S. government's role in facilitating his entry into the country, which would have required a visa and, in all probability, interviews with intelligence officials.
"Amiri made the decision to come to the United States, and he decided who would come with him. He left his family behind; that was his choice," said a U.S. official who asked not to be named because of the diplomatic sensitivity of the matter.
Amiri mentions his family in several of the videos, notably in the most recent, which was posted on YouTube on June 23. Addressing his wife and son, he says, "I wanted to inform my dear family that I am doing well and not to be worried about me. God willing, I will be returning to my dear country Iran in the next few days."
Amiri's claim to have been kidnapped by the CIA was preposterous, several U.S. officials said, noting that someone being held against his will would not have been given access to a computer and a video camera.
His first video claiming to have been kidnapped was his own idea to mislead the Iranian government and protect his family, but he later had second thoughts about claiming to have been kidnapped, the U.S. official said. That prompted the second video posted on YouTube.