State Department: American Citizen Is Missing in Iran

April 2, 2007 — -- An American citizen is missing in Iran, the State Department said today.

Sources tell ABC News that the missing American was a former FBI agent, although they stressed that he was now a private citizen and that his trip to Iran was on "private business" and not associated with official U.S. matters.

State spokesman Sean McCormack said that the United States had been monitoring this case for several weeks and today had sent a message to Iran through diplomatic channels for more information on his whereabouts.

State Department officials say that Iran has yet to respond with any information. Because the United States does not have diplomatic relations with Iran, the message was passed on by the Swiss Embassy in Tehran.

McCormack said the United States had been in touch with the man's family and employer, who were the first ones to report him missing. A senior State Department official tells ABC News the man was last seen in early March in Iran.

The official says that right now nobody seems to know where he is, but that the United States is asking Iran for any information because that's where he was last seen. According to one official, there is "no reliable information" that the American is being detained by Iran.

McCormack denied any connection between this case and that of the 15 British sailors and marines being held by Iran for allegedly straying into Iranian waters in the Persian Gulf.

"There is no linkage with this or any ongoing cases that may have been in the news recently," he told reporters.

The United States has not had diplomatic relations with Iran since the hostage crisis in 1979, when Iranian students stormed the U.S. Embassy in Tehran and held Americans captive for 444 days.

Relations between the United States and Iran have since remained tense, but have been under increased stress in recent years over Iran's nuclear program.

The United States and other Western countries have called on Iran to suspend nuclear enrichment for fear that Tehran is pursuing a nuclear bomb. Iran insists its nuclear program is for peaceful purposes and has defied international calls for suspension.