WASHINGTON - Federal authorities are expected today to reveal a major international undercover sting in which Philadelphia-based federal agents arrested an Iranian arms dealer in Eastern Europe and secretly extradited him to the United States.

The Iranian has been quietly jailed in a Philadelphia-area prison for nearly two years - the case sealed from public view - as U.S. Immigration and Customs Enforcement (ICE) agents have scoured his laptop to pursue hundreds of leads about Iran's covert effort to acquire American military gear, law-enforcement sources said.

"This guy was very prolific - there were five or six years' worth of records related to Iranian procurement on the seized laptop," an official said. "His only customer was and always has been the Iranian government."

The 2007 charges against Amir Hossein Ardebili of Shiraz, Iran, are scheduled to be made public in Wilmington this morning by the U.S. attorney for Delaware, David C. Weiss, and the assistant secretary of U.S. Homeland Security for ICE, John Morton.

The charges against Ardebili, a former Iranian government procurement official, are likely to include a count of violating the International Emergency Economic Powers Act, which essentially prohibits arms and other sales to Iran. He also likely faces money-laundering and conspiracy charges.

Ardebili's lawyer, Edmund D. Lyons, declined to comment last night. The lead prosecutor on the case, David Hall, did not return a phone call yesterday.

U.S. officials said the Ardebili case was unusual because it involved the arrest of an arms dealer living in Iran and working almost exclusively for the Iranian government. The case is rarer still, the officials said, because it involves the successful extradition of an Iranian citizen from a third country to the United States.

Law-enforcement sources said that the undercover ICE agents in Philadelphia made first contact with Ardebili in 2004 over the Internet, and that he began to request a wide variety of military gear, including night-vision equipment and missile parts.

In October 2007, the ICE agents lured Ardebili to an Eastern European country with the promise of buying gyroscopes and radar components. The law-enforcement sources declined to name the European nation involved, but another source confirmed that it was Georgia and that the sting operation took place in the capital of Tbilisi.

The ICE agents, posing as shady U.S. arms salesmen, captured their negotiations with Ardebili on videotape, officials said, and he was arrested by Georgian police on Oct. 2, 2007. Prosecutors in Wilmington won his extradition to the United States from Georgia in January 2008.

To pursue the leads from Ardebili's laptop, U.S. authorities kept the case under wraps in Wilmington for nearly two years. But in recent months the Iranian government and associated groups had begun to make public but cryptic statements about Ardebili.

In October, Iran's foreign minister, Manouchehr Mottaki, complained to the United Nations that the United States had kidnapped or tried to seize four Iranians, including a man identified only by the last name Ardebili. Those reports focused on reports that some of the men were nuclear scientists. Ardebili is believed to be an engineer and arms dealer; there is no indication that he bought or tried to buy any nuclear-related items, a U.S. official said.

According to an Iranian newspaper account translated by the BBC, the foreign minister alleged that Ardebili was a merchant who was improperly extradited from Georgia to the United States. According to news accounts at the time, the foreign minister raised the issue of the four Iranians during a face-to-face meeting with U.N. Secretary General Ban Ki-moon.

The ICE investigation is part of a larger effort to prevent sensitive and restricted technology from making its way to Iran and China. According to U.S. government reports, the majority of prosecutions in such cases - including the illegal export of stealth technology, military aircraft components, warship data, and night-vision equipment - have involved Iran or China.

ICE, the FBI, and other law-enforcement agencies have arrested hundreds of people who have violated export laws that ban unlicensed sales of sensitive military equipment and any military sales to Iran and other hostile nations. In fiscal 2007 and 2008, ICE made 333 such arrests, the agency says on its Web site.

Nearly all of those cases were made against buyers or sellers inside the United States. Last week, for example, a Belgian national pleaded guilty, following his arrest in New York, to conspiracy to export F-5 fighter-jet engines and parts to Iran. Later this month, a Chester County business owner named Ali Amirnazmi is scheduled to be sentenced in Philadelphia for illegally selling chemical-related software to Iran.

The Ardebili investigation is not related to a pair of terrorism cases unveiled last week in Philadelphia. In those cases, FBI and ICE undercover agents allegedly sold shoes, video games, and ultimately machine guns and military gear to people in Michigan, Slovakia, and Lebanon with links to the group Hezbollah.

Contact staff writer John Shiffman at 301-320-6655 or jshiffman@phillynews.com.