Ahmad Wali Karzai, brother of Afghan President Hamid Karzai. — Photo by AP

KABUL: The Taliban claimed responsibility for the assassination of President Hamid Karzai's younger brother on Tuesday, calling it “one of our biggest achievements” in nearly a decade of war.

Taliban spokesman Usuf Ahmadi told AFP by telephone that the group had recently assigned a gunman to kill Ahmed Wali Karzai, a hugely powerful and controversial figure in the Afghan south.

A senior official in Afghanistan's spy agency said the younger Karzai had been shot dead in his home by an old friend called “Sardar Mohammad” who was killed by bodyguards following the assassination.

“This is one of our biggest achievements since the (spring) operation began. We assigned Sardar Mohammad to kill him recently and Sardar Mohammad is also martyred,” said Ahmadi.

Initial details were sketchy, but a family friend, speaking on condition of anonymity, told AFP that Wali Karzai had been killed by a bodyguard while entertaining guests at home. “We can confirm he has been martyred,” Kandahar provincial government spokesman Zalmay Ayubi told AFP, providing no further details.

A health official, also speaking on condition of anonymity because of the sensitivity of the information, said Wali Karzai had been shot dead.

The assassination came as Afghan President Hamid Karzai was to hold talks with French President Nicolas Sarkozy, on a surprise visit to Afghanistan where he announced that Paris would recall 1,000 soldiers by the end of next year.

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

American documents leaked by Internet whistleblower WikiLeaks late last year also painted him as a corrupt drugs baron, but Western officials always kept quiet in public on the president's younger half brother's tainted record.