Ahmad Wali Karzai, a half brother of Afghan President Hamid Karzai and one of the most powerful men in southern Afghanistan, was killed on Tuesday, said an official.

"I confirm that Ahmad Wali was killed inside his house," said Zalmay Ayoubi, spokesman for the governor of Kandahar province, where Ahmad Wali Karzai lived. He was the head of the provincial council.

A cousin of Ahmad Wali Karzai, who asked not to be named, also confirmed the news.

The Telegraph quoted a family friend, speaking on condition of anonymity, as saying that Karzai had been killed by a bodyguard while entertaining guests at home.

Wali Karzai, head of Kandahar's provincial council, was a deeply controversial figure in Afghanistan. He was dogged by allegations of unsavoury links to Afghanistan's lucrative opium trade and private security firms.