Usama bin Laden's former driver has been released from a Yemeni prison after serving out his sentence, according to his lawyer.

Lawyer Khaled Al-Anas said Salim Hamdan was released Friday.

A Yemeni Interior Ministry official has confirmed the release but says it happened Saturday. He spoke on condition of anonymity because he was not authorized to talk to the media.

The reason for the discrepancy was not clear.

A U.S. military tribunal convicted Hamdan in August of aiding Al Qaeda and sentenced him to 5 1/2 years in prison. He had already served five years and a month at Guantanamo Bay prison at the time.

The U.S. transferred Hamdan to his home country Yemen at the end of 2008 to serve out the rest of his sentence.