TEHRAN – Iran summoned the Swiss ambassador in Tehran on Tuesday and handed over documents which it said showed a missing Iranian nuclear scientist had been kidnapped by the United States, IRNA news agency reported. Iran has no diplomatic relations with the United States and U.S. interests in Tehran are handled by the Swiss embassy. Shahram Amiri, a university researcher working for Iran's Atomic Energy Organization, disappeared during a pilgrimage to Saudi Arabia a year ago and Tehran accused Riyadh of handing him over to the United States, a charge Saudi Arabia has denied. Iran's state television showed a video on Monday of what it said was Amiri. In the footage, Amiri said he had been kidnapped and taken to the United States where he was "tortured." However, in a new video on youtube.com, also reported to be of Amiri, he said he was actually studying in the United States. "I am in America and intend to continue my education in this country. I am free here and assure everyone I am safe." He did not specifically address the abduction allegations, but said he had not taken any action against Iran. The man in both videos looked similar to photographs of Amiri that have appeared previously in Iranian media, although neither of them could be independently verified by Reuters. "In the meeting (with the Swiss envoy) Iran emphasized that America is responsible for the life and well-being of Mr. Amiri and stressed his abduction was against all obvious international laws and human rights," the official IRNA agency said. "Also documents regarding the abduction of Amiri were handed to the Swiss ambassador," IRNA said, adding that Iran's Foreign Ministry had asked for the immediate and unconditional release of Amiri. In March, ABC news said Amiri had defected to the United States and was helping the CIA. A CIA spokeswoman declined to comment on the U.S. network's report. In the video shown on Iran's television on Monday, Amiri said he had been forced to take part in an interview "with an American media source to claim that I was an important figure in Iran's nuclear program and that I had sought asylum in America of my own free will." Amiri said in the video he was in Arizona in the United States and that the footage was taken on April 5 this year. He urged human rights groups to help him return to Iran. Tehran initially refused to acknowledge Amiri's involvement in Iran's disputed nuclear program, which Washington and its allies suspect is being used to develop nuclear weapons. Iran says it is aimed at generating electricity. Three months after Amiri's disappearance, Iran disclosed the existence of its second uranium enrichment site, near the central holy Shi'ite city of Qom, further heightening tension over the Islamic state's atomic activities.