Sher Muhammed Akhunzada has managed to place allies in key official posts in the provincial administration and, according to Afghan officials and western diplomatic sources, is trying to undermine the current governor, Assadullah Wafa.

The removal of Mr Akhunzada, who runs his own private army, is said to have been one of the pre-conditions for the deployment of British forces to Helmand in 2006. His reinstatement, if it takes place, is likely to cause serious problems for Britain, which has made Helmand the focus of its main military and financial commitment in Afghanistan. It would also raise further questions about President Hamid Karzai's judgement and his failure to deal with corrupt officials. Yesterday, Mr Wafa flew from Lashkar Gar, the the capital of Helmand, to Kabul to meet President Karzai to discuss his future. A suicide bombing which injured three civilians in Lashkar Gar a few hours before Mr Wafa left would strengthen the hands of critics who have complained about his failure to defeat the Taliban.

The governor, who is elderly and in poor health, may well welcome a move from his high-pressure job in the frontline of the war against the Islamists and the drug-dealers who produce 50 per cent of Afghanistan's opium poppies. Mr Wafa has been at a disadvantage because he is from Spin Boldak, near Kandahar, and not a Helmand native. Mr Akhunzada, however, has strong roots in the area and, while governor, built up a reputation for tackling the Taliban – although some of his methods were extremely brutal.

Mr Akhunzada has maintained close and cordial relations with President Karzai, who appointed him to parliament. He subsequently hired 500 mercenaries to buttress his power base in Helmand.

Mr Karzai asked Mohammed Daoud, a British protégé, to replace Sher Mohammed as governor but also installed Mr Akhunzada's brother, Amir Muhammad Akhunzada, who is accused of assorted criminal acts. That decision was seen as an attempt to placate the Akhunzada family's powerful tribal following.

However, Amir Muhammed was accused of constantly undermining Mr Daoud and later fired – to the consternation of the British. The machinations of the Akhunzadas were blamed for Mr Daoud's departure, although there were also claims the Americans played a part. They were said to be unhappy that Mr Daoud signed the Musa Qala agreement, under which British and Nato forces agreed to stay out of the town of Musa Qala in northern Helmand in return for tribal elders pledging to fight the Taliban.

US officials, however, claim the Musa Qala deal was a sham which allowed hundreds of Taliban to move into the town in February this year. General Dan McNeill, who succeeded the British General David Richards as the leader of Nato forces in Afghanistan, reportedly said the treaty was "an intellectual mistake and a strategic disaster". Musa Qala district remains in Taliban hands. Hawks in Mr Karzai's cabinet want the area cleared but British commanders insist military action will only be sanctioned once a reconstruction programme is in place.

It is unclear how Afghan security forces would react if the Akhunzadas return. When Mr Daoud was deposed, the then provincial police chief, Nabi Jan Mullahkhail, was asked how he would feel about serving under the brothers. "Rather than work for them, I would quite like to arrest them," he said. "They have been responsible for much of Helmand's misfortune."