TEHRAN, Iran -- The disappearance of an Iranian nuclear scientist on a pilgrimage to Saudi Arabia in June is raising questions about whether he defected and gave the West information on Iran's nuclear program.
Iran's foreign minister on Wednesday accused the United States of involvement in the disappearance of Shahram Amiri, who reportedly worked at a university linked to the elite Revolutionary Guard military corps.
In a sign of the sensitivities surrounding Amiri, Iranian officials have not even publicly identified Amiri as a nuclear scientist, referring to him only as an Iranian citizen. Amiri's wife has said he was researching medical uses of nuclear technology at a university and was not involved in the broader nuclear program.
Iran's foreign minister took the unusual step of complaining to the head of the United Nations last week about the disappearance, at the same time raising the case of a former defense minister who vanished in Turkey in 2007, also believed by many to have defected.
Amiri vanished several months before the September revelation of a uranium enrichment facility near the city of Qom, which the United States and its allies accuse Iran of building secretly. The timing has led experts to question whether Amiri may have given the West information on it or other parts of Iran's nuclear program.
The discovery of that facility was a coup for Western intelligence. Iran denied trying to hide the site, insisting it was not yet required to declare it to the U.N. nuclear watchdog. Still, it was put on the defensive as it entered landmark nuclear negotiations with the U.S. and other world powers last week, talks that have somewhat eased rising tensions between the two sides.
U.S. officials have said multiple streams of intelligence -- particularly spy satellites -- were used to reveal the Qom site and its function, but they have not specified whether the sources included Iranians on the ground.
The United States and its allies accuse Iran of secretly seeking to develop nuclear weapons, a claim Iran denies, saying its program is intended only to produce electricity.
Little is known about Amiri, and his fate remains a mystery after more than four months.
Iran has asked Saudi Arabia for information on his whereabouts but has received no reply, Foreign Ministry spokesman Hasan Qashqavi said earlier this week. Amiri's relatives have demonstrated several times outside the Saudi Embassy in Tehran demanding information.
The Iranians "may be concerned that the Americans were involved in luring him away," said Meir Javedanfar, an Iranian-born analyst based for the Middle East think tank, meepas. He raised the possibility Amiri was willingly offering information to the West, despite Iranian claims he was arrested in Saudi Arabia.
"There's the possibility he was taken away in a limousine rather than being shoved in the back of a car, meaning that he could have been a walk-in," said Javedanfar, who is based in Israel.
Amiri worked as a researcher at Tehran's Malek Ashtar University, according to Iran's state-run English language channel Press TV. The university has been cited by the U.N. in the past as a nuclear research site and is widely thought to be run by the Revolutionary Guard.
One Iranian news Web site claimed Amiri had worked at the Qom facility and had defected in Saudi Arabia. The Web site, Jahannews, which is connected to Iranian conservatives, gave no source for the report.
Amiri traveled to Saudi Arabia on May 31 for Omra, an Islamic pilgrimage to Mecca, his wife told the unofficial news agency ISNA. The last she heard from him was on June 3, when he called her from the holy city of Medina.
She said he told her that during his arrival in Saudi Arabia, he had been questioned extensively by police at the airport -- "more than any other passenger," according to ISNA, which did not give the wife's name.
Foreign Minister Manouchehr Mottaki raised the level of interest Wednesday, saying that Amiri had been arrested and accused the United States of a role.
"We've obtained documents about U.S. involvement over Shahram Amiri's disappearance," Mottaki said, according to the semiofficial Fars news agency.
"We hold Saudi Arabia responsible for Shahram Amiri's situation and consider the U.S. to be involved in his arrest," Mottaki said, quoted by the official IRNA news agency. "We regard Saudi government as responsible for Amiri's condition and according to some documents available for us, we consider that the US is responsible for his detention."
ISNA, an Iranian student news agency, said Mottaki addressed reports that Amiri was on the staff of Atomic Energy Organization of Iran, saying "these are speculations discussed by western media and we pursue his case as an Iranian national."
There was no immediate comment from Saudi officials. In Washington, State Department spokesman Ian C. Kelly said he had no information about the matter. "The case is not familiar to us," Kelly said.
The Arab newspaper Asharq Al-Awsat, which is owned by Saudi businessmen, reported last week that Mottaki made a formal complaint to U.N. chief Ban Ki-moon about the disappearances of Amiri and several other Iranians in recent years, some of whom it feared may have provided nuclear information to the West. Qashqavi this week denied the complaint made any mention of the nuclear issue.
In New York, U.N. spokeswoman Michele Montas said "the issue was raised at a tete-a-tete meeting" between Ban and Mottaki and she had no further details.
Also on the list Mottaki handed over was Ali Reza Asghari, a retired general in the elite Revolutionary Guard and a former deputy defense minister, who disappeared during a private visit to Turkey in December 2007. Iran accused Western intelligence services at the time of possibly kidnapping the official, though other reports have said he may have defected.
Another Iranian on the list was a man identified only by his last name, Ardebili, who was reportedly arrested in the Caucasus nation of Georgia recently. Qashqavi said Monday that Ardebili was a businessman and accused Georgian authorities of arresting him and handing him over to the United States. Asharq Al-Awsat identified him as a nuclear scientist, but gave not sourcing for the claim. A Georgian government spokesman in Tbilisi refused to comment.
Lee Keath reported from Cairo. AP correspondents Steven Weizman in Jerusalem and Misha Dzhindzhikhashvili in Tbilisi contributed to this report.