The Pakistani Prime Minister has condemned the murder of the half-brother of Afghanistan’s President Hamid Karzai as “an act of cowardice”.

Yousuf Raza Gilani telephoned Karzai to deliver his condolences for his loss, although relations between the two South Asian neighbors have been strained over accusations of cross-border attacks by militants.

In a statement, Gilani’s office said he expressed “shock and grief” over the death of Ahmed Wali Karzai.

Wali Karzai, who has faced accusations of being involved in the drug trade as well as corruption, was nonetheless a strong ally of his elder half-brother.

The Taliban has claimed responsibility for his death, calling it ''one of our biggest achievements.”

However, the Sydney Morning Herald reported that Wali Karzai was murdered by his own bodyguard, who was part of his inner circle form several years, raising doubts about Taliban culpability.

He was reportedly shot three times in the southern state of Kandahar as he met with a group of tribal leaders.

President Karzai later told a news conference:”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.''