Ahmad Wali Karzai, the head of Kandahar Provincial Council, speaks with international media following a shura held in Kandahar, in this June 14, 2010 file photo. Ahmad Wali Karzai, a brother of Afghan President Hamid Karzai and one of the most powerful men in southern Afghanistan, was killed on July 12, 2011, an official and a family member confirmed.[Photo/Agencies]

KANDAHAR, Afghanistan - Ahmad Wali Karzai, a brother of Afghan President Hamid Karzai and one of the most powerful men in southern Afghanistan, was shot dead on Tuesday, apparently by one of his bodyguards, officials said.

He was a controversial figure, but his assassination will leave a dangerous power vacuum in Kandahar, the Taliban's birthplace and a focus of recent efforts by a "surge" of US troops to turn the tide against the insurgency.

"My younger brother was martyred in his house today. This is the life of all Afghan people, I hope these miseries which every Afghan family faces will one day end," President Karzai said at the start of a news conference with his French counterpart Nicolas Sarkozy in Kabul.

The Interior Ministry said he was shot dead, and Abdul Ghafar Sayedzada, head of the ministry's counter-terrorism department, said the killing was probably the work of someone from his inner circle.

"It appears Ahmad Wali Karzai has been killed by one of his bodyguards, and there was nobody from outside involved," Sayedzada told Reuters.

Ahmad Wali, the head of Kandahar's provincial council, had survived two other assassination attempts in recent years. He said in May 2009 that he had been ambushed on the road to Kabul by Taliban insurgents, who killed one of his bodyguards in an early morning attack.

In November 2008 he also escaped unscathed from an attack on government buildings in his home province which killed six.

The Taliban claimed responsibility for the attack, saying they had persuaded one of Karzai's bodyguards to turn on him. The hardline insurgent group often exaggerate battlefield claims, however, and in the past have taken responsibility for attacks that security services question their role in.

CRITICAL POWER BROKER

A half brother of the president, Ahmad Wali was a critical power-broker who helped shore up Karzai's influence in volatile southern Afghanistan.

He returned to Afghanistan after the ouster of the Taliban government, leaving behind a career as a restaurateur in Chicago to eventually become probably the most powerful man in Kandahar.

His power came not from his position as head of the provincial council -- which normally carries limited influence -- but from his tribal and family connections and the fortune he accumulated.

He had been accused of corruption and ties to Afghanistan's huge opium trade that helps fund the Taliban-led insurgency. Ahmad Wali had denied the accusations.

Foreign officials saw Ahmad Wali as a polarizing figure who could complicate their efforts to win over the population and supplant the Taliban by bringing improvements to the way the province is governed.

But they also recognised his huge reach and worked closely with him despite misgivings.

The United Nations said in a recent quarterly report that over half of all assassinations across Afghanistan since March were in Kandahar.