The family of the British aid worker Margaret Hassan today said that a court's decision to acquit two of three Iraqis charged with her murder was a "green light" to kidnappers.

Mrs Hassan's relatives also criticised the British Government's "inept" handling of her abduction and chastised detectives for their "incompetent" investigation which led to today's acquittals.

One of the three accused, Mustafa Salman al-Jabouri, was jailed for life after a hearing lasting only two hours before a panel of judges in Baghdad. He was found guilty of aiding and abetting the kidnappers who snatched Mrs Hassan, 59, as she drove to work in October 2004.

Mrs Hassan's family believe that police failed to gather evidence which would have led to al-Jabouri's conviction for murder, for which there is a mandatory death sentence.

Mrs Hassan, who had lived in the country for 30 years with her Iraqi husband, Tahseen Ali Hassan, was well known for her work among impoverished Iraqis as the head of the local arm of the CARE International charity.

After her abduction, she appeared in a series of increasingly distressing video messages before she was shot dead a month later. Her body has never been found.

According to court officials quoted by Reuters, al-Jabouri received a plastic bag containing her purse and other documents from a friend. The bag was found by Iraqi police when they raided his farm in May 2005.

In a statement, Mrs Hassan's brother, Michael Fitzsimmons, and sisters, Deidre, Geraldine and Kathryn, revealed that the kidnappers contacted Tahseen Hassan four times using his wife's mobile telephone in the run-up to her murder, demanding to talk to a member of the British Embassy.

Mr Hassan pleaded with the British team to open a dialogue with the caller but was rebuffed by officials who argued that they did not negotiate with hostage takers.

In a separate statement released following today's verdicts, Mrs Hassan's relatives said that her memory had been betrayed by the failures of the authorities.

It said: "Mustapha Al-Jabouri was found guilty of ’joining the group who kidnapped Margaret’.

"This man was found with Margaret’s personal belongings. He had used her mobile telephone up until the eve of her death, to make demands of her husband Tahseen.

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