Pat Kember used a 30-second film shown by the Arab broadcaster al-Jazeera last night to tell the hostage-takers that her husband was a good man who believed in peace and had come to Iraq to help its people.

In a videotape broadcast by the station last week, the kidnappers threatened to kill Mr Kember and three other hostages on Thursday unless all prisoners in US and Iraqi detention centres were released.

Mr Kember, 74, from Pinner, northwest London, was seized in Baghdad more than a week ago with two Canadians and an American. He had gone to Iraq with Christian Peacemaker Teams, a Canada-based peace group, as a gesture of solidarity.

Mrs Kember told viewers that her husband had “throughout his life bravely fought against all kinds of injustice.

“Please release Norman and his colleagues so that they can continue their work for the sake of peace in Iraq,” she said.

“They are friends and allies who want to help you to overcome evil by engaging in a humanitarian action.”

A leader of the Muslim Association of Britain, Anas Altikriti, who is of Iraqi origin, has spent a second day in Iraq meeting Sunni Muslim groups in Baghdad to try to win the release of Mr Kember and the other hostages. Mr Altikriti said last night that he was “encouraged and optimistic” after a generally positive reaction in the city.

In a separate development, legal tussle is under way between British military and government lawyers over whether soldiers engaged in combat should be charged in fatal shooting incidents involving “civilians”.

Major-General Peter Wall was General Officer Commanding Multinational Division Southeast in southern Iraq last year when legal doubts were raised about how Sergeant Steven Roberts and an Iraqi, Zahir Zabti Zaher, died. General Wall queried whether a criminal investigation was justified. His intervention was one of the reasons Lord Goldsmith, QC, the Attorney-General, removed the case from military jurisdiction and handed it to the Crown Prosecution Service, which asked the Metropolitan Police to investigate whether there were grounds for criminal charges.

Legal sources said that the general could face questioning as part of the inquiry after Lord Goldsmith said in published correspondence with Geoff Hoon, then Defence Secretary: “There is evidence which could be taken to show a concerted attempt by the chain of command to influence and prevent an investigation.”

Sergeant Roberts, 33, of the 2nd Royal Tank Regiment was killed by “friendly-fire” in 2003 when his comrades opened fire at Mr Zaher, who had attacked him with bricks. According to military sources, the Iraqi “civilian” was in war paint and behaving like a “combatant”. In this situation soldiers may use lethal force to protect themselves. Army legal advisers ruled that Mr Zaher was a combatant and the death of Sergeant Roberts had been a tragic error. But the case was reviewed by the military police and the lawyers found, after all, that Mr Zaher was a civilian.

No decision has been made about charging anyone over the deaths.

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