The trial of an alleged "sleeper agent" for Saddam Hussein's intelligence service began Tuesday with a federal prosecutor accusing him of spying on Iraqi dissidents in the United States.

Sami Latchin, a 59-year-old Iraqi-born U.S. citizen, is accused of spying on U.S.-based critics of the deposed Iraqi dictator, who was hanged Dec. 30.

"There is a spy in this room," Assistant U.S. Attorney James M. Conway told jurors in the courtroom of U.S. District.

Latchin is not accused of espionage — an offense that involves obtaining U.S. military secrets. Prosecutors say his spying was aimed only at Iraqi civilians in the United States.

The former airline employee was arrested in August 2004, when prosecutors unsealed an indictment charging him with making false statements to immigration authorities on a U.S. citizenship application.

Authorities claim he failed to disclose that he had been a member of the Baath Party and had served in Iraq's intelligence service. If convicted on all counts, Latchin could face a maximum of 25 years in prison.

Three former Iraqi intelligence officers are expected to testify against him. Defense attorney Mary Higgins Judge called them "professional, career, trained liars."

"By definition their job involves trickery, deceit and pretending," she said. "It is what they have done all their lives."

Two of the three former Iraqi intelligence officers are planning to testify under pseudonyms — "Mr. Khalil and Mr. Ali" — and in disguise out of concern about reprisals.

The third, Muhammad Al-Dani, used his real name during testimony later Tuesday but appeared in disguise. He wore thick glasses, a mustache and a mop of black hair that looked suspiciously like a toupee.

Al-Dani testified that he was once the Washington station chief of the intelligence service.

Conway led Al-Dani through a series of letters in which an Athens-based Iraqi agent named Sami Khoshaba recruited "collaborators" who would go from there to the United States and Canada and become informants.

Prosecutors claim that after his stint in Greece, Latchin moved to the United States, where he continued his work as an intelligence operative.

Khoshaba is Latchin's middle name and he once lived in Athens. Prosecutors say he is the person named in the letters. Defense attorneys admit the name similarity without agreeing to the rest of the allegation.

Latchin's attorney said Al-Dani had been paid "close to a million dollars" as a government witness and suggested he had to come up with testimony to justify the money. She called it his "million-dollar story." Conway said the amount was closer to $700,000 or $800,000.

Al-Dani testified that he was not required by his deal with the government when he defected from Iraq to testify at a criminal trial.