The Department of Foreign Affairs has established contact with authorities in Iraq in a bid to verify reports that a group of insurgents arrested on Sunday had admitted involvement in her killing.
Officials are also seeking confirmation that articles of clothing and personal items found during the raid by Iraqi and US troops belonged to Mrs Hassan.
An official at the British Embassy in Baghdad confirmed a “direct link” between the seized items and the murdered aid worker.
“Articles were found which established a direct connection to Margaret Hassan, including documentary evidence,” the official said.
Suggestions the items included a purse, a woman’s shirts and trousers, and documents bearing the CARE logo and signed by Mrs Hassan, have yet to be confirmed.
US central command has yet to publicly release full details of the operation which took place in an area about 30 km south of Baghdad known as a stronghold for anti-coalition militants. Four men are being questioned about her kidnapping.
A spokesman for the Department of Foreign Affairs said last night that detailed information about the operation was still being sought but officials were on standby to respond as needed.
“We are very much ready and waiting to give all our consular and other assistance that the Hassan family require from us.
“We are also in contact with the British Foreign Office through the Irish Embassy in London. We have asked the Embassy to monitor the situation and report to us any new information.”
While the arrests were carried out in a joint US-Iraqi operation, British authorities in Baghdad have been keeping a close watch on Mrs Hassan’s case.
There has been no news of Margaret Hassan, 59, since last November when a video, released to media but not broadcast, showed the execution of a woman.
She had been abducted a month earlier on her way to work in Baghdad, where she lived for 30 years with her Iraqi husband and ran aid agency CARE International’s Iraqi operation.