Senior judges have upheld a landmark ruling that will force police across the country to take legal responsibility for the protection of their witnesses.

Hertfordshire Police was found to have failed in its duty of care for Giles van Colle, 25, who was shot with a silver bullet days before he was due to testify in court. The Court of Appeal has backed a High Court decision today enshrining in law the police's legal duty to protect witnesses.

Van Colle, an optician in north London, was murdered by his former employee Daniel Brougham shortly before he was due to give evidence against him in November 2000. Van Colle had informed the police that he had been threatened by Brougham.

The Master of the Rolls, Sir Anthony Clarke, sitting with Lord Justice Sedley and Lord Justice Lloyd, dismissed the Hertfordshire force’s appeal, despite police concerns that the payout may open the floodgates to a series of similar claims under the Human Rights Act.

The judgment handed down at the Court of Appeal stated that “the police should have taken action to protect Giles.

"They should have known that there was a real risk to his life and that the risk was and would remain immediate until the date of Brougham’s trial. In these circumstances they should have done all that could have been reasonably expected.”

The judgment explained that: “Unfortunately…the police did nothing.”

The Home Office said it is working on national guidelines to set standards for witness protection policies, but insists it is down to individual chief officers to implement their own procedures.

“Since this murder there have been tough new laws, which clarified roles and responsibilities for witness protection programmes,” a Home Office spokeswoman said. “It’s for individual chief officers not Home Office Ministers to make a decision on witness protection.”

Police forces have begun to consider their witness protection policy, with Irwin van Colle, Giles’s father, speaking at conferences and addressing Humberside Police force about the circumstances of his son’s death.

The police may be forced to introduce a clearer and more rigorous policy after the judgment concluded that Van Colle’s human rights, as enshrined in the Human Rights Act and European Convention on Human Rights, were compromised. The judges said that “the police infringed Giles’ right to life under article 2 of the Convention”.

The family of the optician, who was shot three times as he sat in his car in Mill Hill, North London, had their right to police compensation upheld, although the sum was reduced from £50,000 to £25,000.

Hertfordshire Police accepted that the officer in charge of the case, Detective Constable David Ridley, had “failed to perform his duties conscientiously and diligently”, but denied liability for Van Colle’s death.

Irwin van Colle, a Conservative councillor in Brent, north London, said: “There is now a convergence of human rights law and common law, which will have a significant impact on the public sector in particular and on society in general.

"Witnesses, as a class, will have their welfare better served than before, which will help to protect the lives of many from ongoing intimidation in the future.”

Brougham was convicted of the murder of Van Colle in March 2002. The 36-year-old, who was born in Iran as Ali Amelzadeh, had been employed by Van Colle as a laboratory technician for three months during 1999 but was dismissed after equipment was stolen.

Van Colle was asked by police to identify property and to be a witness at Brougham's trial for theft from three companies, including his own practice.

In the lead up to Brougham’s court appearance he repeatedly threatened Van Colle and attempted to bribe other witnesses. In September 2000 the optician's car was found on fire in front of the family home. A second witness in the Brougham case also reported intimidation and two fires of his own, one in his wife’s car and another at his business address.

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