Abuzeid, who was found guilty for the killing of U.S. diplomat John Granville, was released by the country's high court two years after a settlement was reached between the Sudanese government and Granville's family, his brother said.
The U.S. State Department did not immediately respond to a request for comment.
Granville was attacked on January 1, 2008 while being driven home from the British Embassy in Khartoum. He was ambushed by two gunmen, according to authorities who block his car's route.
The gunmen killed his driver, Abdel Rahman Abbas, immediately. Granville died several hours after the attack suffering from gunshots in the chest and in the neck.
A militant group, Ansar al-Tawhid (Companions of Monotheism) claimed responsibility via a post four days later on a website used by Islamists
