Zahra Abdullah has won a civil action for damages from President Abdullahi Yusuf for her husband's death in the high court and she is urging Britain to detain him as it did the former president of Chile, Augusto Pinochet.

Mr Yusuf, 70, a warlord, is recognised by Britain as the head of the transitional government of Somalia in exile. He is in Britain for medical treatment following a liver transplant.

The president has been accused in connection with the murder of Sultan Ahmed Mohamud Mohamed, a British citizen, who was killed in the village of Kalabeyr in Somalia in August 2002. He was a political leader who had returned from exile in London and was hoping to resettle in his country, his widow told the Guardian. He had been critical of Mr Yusuf.

According to evidence given earlier this year in a high court civil action, the murdered man had driven past a convoy led by Mr Yusuf and had been spotted. Two vehicles peeled off from Mr Yusuf's convoy, and their armed occupants tracked down Sultan Ahmed and shot him dead. Such deaths are not uncommon in Somalia and would not normally be investigated, but because Mr Yusuf was a frequent visitor to Britain, Sultan Ahmed's widow decided to pursue the case here.

Ms Abdullah lives with her four children in west London, where she works as an interpreter. She married her husband in 1986 in Nairobi. Both were granted refugee status in Britain and later citizenship. He studied accountancy and business in London but was unable to obtain regular employment here.

For this reason, she said, he returned to Somalia, which has been in political turmoil for the past 14 years. With the support of some people in the Somali community in London she brought a civil action against the president, accusing him of being responsible for the death of her husband and seeking damages.

Mr Yusuf, through his British lawyers, entered a written defence to the action. In it he denied direct or indirect involvement in the killing. He said the action was "politically motivated", the murder would be investigated in Somalia and "blood money" would be paid.

But the court did not accept that there was any redress possible in Somalia in its current state. The court referred to evidence that Mr Yusuf had met challenges to his presidential claims "with lethal force" and noted that "his supporters are reported to have carried out retaliations, including executions, against his opponents".

Last month judgment was given against Mr Yusuf on the grounds that he had failed to comply with a court order to produce documentation for his defence, and so there was no full trial. He was ordered to pay £10,000 "bereavement damages" to Ms Abdullah.

The judgment found "the evidence does not show that the defendant was personally responsible for the killing of the deceased but it appears that the killing was carried out by those acting under his authority and under his command".

Mr Yusuf has paid £30,000 in damages and costs. Now Zahra Abdullah wants him to face criminal charges and her lawyer, Michael Hanley, has sent a dossier on the case to Scotland Yard.

"All I want is some justice for my husband," she said at her home in White City. "The men who killed my husband were Abdullahi Yusuf's troops, under his command. My husband was unarmed and had no bodyguards - he was a civilian.

"It is three years since he was killed and there has been nothing. I think that he thought that by paying the money in the court case that would be an end of it but we want to see him detained so that he cannot go back to Somalia."

She said that she believed the case of General Pinochet, who was detained in Britain pending extradition proceedings because of crimes committed in Chile, set a precedent for the UK to act.

"Britain has a wonderful opportunity to help the peace process in a constructive way by prosecuting warlords," Mr Hanley said yesterday.

There was no response from Mr Yusuf to messages left for him at the contact numbers given on his behalf to the Guardian or via his legal representatives. The Cromwell hospital, in west London, where he was described as having treatment, said no one of that name was registered with it.