Ahmed Wali Karzai, half brother to the Afghan president and one of the most powerful men in the country, has been killed in Kandahar city by a close associate.

Sardar Mohammad, the man who killed Wali Karzai, was reportedly a dear friend who had been promoted on Karzai's recommendation to become a local security checkpoint commander with more than 100 men under his command.

Wali Karzai was the head of Kandahar's provincial council, but his influence extended far wider, and he was reported to be involved in the country's drug trade as well as on the payroll of the CIA.

Al Jazeera's Nazanin Sadri reports.