Salim Hamdan was transferred to Yemeni custody and taken to a state security prison after he arrived at a military base at San'a International Airport Wednesday night, a Yemeni security official said.
Hamdan was the first man to go before a U.S. war crimes trial since the end of World War II. He was convicted on Aug. 6 of providing material support to terrorism, and the military said it could keep him locked up indefinitely if it considered him to be a continued threat. Instead, he was sent back home to Yemen early.
Hamdan's U.S. military attorney said the 40-year-old father of two was incredulous when he learned Saturday he being sent home to Yemen.
"The defense team spoke to him on the telephone on Sunday morning. He was still in a state of disbelief," Navy Lt. Cmdr. Brian Mizer said Wednesday. "He thanked each of us for our work on the case and we agreed to speak again soon when he was in Yemen."
Hamdan was sentenced at the trial to 5½ years in prison. He was credited with five years and one month time served so his sentence ends on Dec. 27, the Pentagon has said.
His family in Yemen asked to greet him when he arrived, but the government denied their request, said the Yemeni official, who spoke on condition of anonymity because he was not authorized to release the information.
Hamdan has never seen his 7-year-old daughter, his attorney said.
Mizer said he did not know what set-up the Yemeni authorities have for keeping Hamdan detained until his release date.
Yemen is the ancestral homeland of bin Laden, and the site of the al Qaeda attack on the USS Cole in 2000.
Guantanamo prosecutors sought a sentence of 30 years to life for Hamdan and they argued that he should not receive credit for his time detained at Guantanamo. A military judge rejected that argument and called Hamdan a "small player."
The jury of military officers convicted him of supporting terrorism but acquitted him of being part of al Qaeda's conspiracy to attack the United States. He was also cleared of providing missiles to al Qaeda and knowing his work would be used for terrorism.