ALEXANDRIA, Va. — A U.S. contractor who worked at the notorious Abu Ghraib prison in Iraq was sentenced to more than three years in prison Friday for possessing child pornography that he obtained using the prison’s computer network.

Ahmed Hasan Khan, 31, of Woodbridge, had been working at Abu Ghraib for contractor L-3 Communications Holdings Inc. in November 2005 when a network administrator at the prison saw that Khan had been visiting suspicious sites. A search of Khan’s laptop computer later found hundreds of child pornography images, including children as young as 4, officials said.

Khan apologized at Friday’s sentencing hearing.

“I let my country down at a time when it needed its armed services the most,” he said.

The three-year, five-month sentence imposed by U.S. District Judge Claude Hilton was at the low end of sentencing guidelines. Prosecutor Jerry Smagala told the judge that such a sentence would be appropriate.

It is not clear exactly what kind of work Khan was doing at Abu Ghraib. Court records indicate he held a security clearance that was revoked after the investigation.

His lawyer, public defender Suzanne Little, said during Friday’s sentencing that Khan “was working long hours in an intensive program that I can’t say much about in court.”

An L-3 spokeswoman declined to comment. The company has contracts for translators and other services in Iraq.

Federal prosecutors brought the case against Khan under the Military Extraterritorial Jurisdiction Act, which allows for military contractors to be prosecuted in federal courts for crimes they commit while overseas.

Photos of torture and humiliation of prisoners at the Baghdad prison, first revealed in 2004, embarrassed the Pentagon and shocked the Muslim world.