An Afghan official says Afghan President Hamid Karzai's half brother has been killed in southern Afghanistan.

Zalmai Ayubi, the spokesman for Kandahar province, says that Ahmad Wali Karzai was shot dead on Tuesday.

A provincial health official and a security guard protecting Ahmad Wali Karzai, who both spoke on condition of anonymity, also confirmed the shooting.

Ahmad Wali Karzai, who was head of the Kandahar provincial council, had become a political liability for the Karzai government a symbol of cronyism and a lightning rod for criticism of all that is wrong with the Karzai administration.

But the president repeatedly defended him, denouncing accusations that his brother was involved in criminal activities.