When a Brighton woman's teenage son froze to death in a tragic accident she fought a three-year battle to get police policy changed.

But six years on Jane Shelley fears the policy has been shelved or forgotten by Sussex Police.

Mrs Shelley and her husband David were devastated when one of their six children, 17-year-old Matthew, was found dead behind flats in Hollingbury, Brighton.

Matthew had been experimenting with alcohol. On January 6, 1997, Matthew and two of his friends bought three litres of whisky.

They spent the afternoon drinking at one of the boy's homes.

Later they caught a bus to Hollingbury and met two girl friends. The group then caught another bus to nearby Carden Park.

The gang huddled near the community centre chatting and drinking.

It was a very cold night, with frozen snow and ice on the ground.

Sometime after 2.30am, the whisky finished, Matthew said he was going for some cigarettes and headed off alone in the direction of home.

But he never made it.

He was heard at the rear of a block of flats about a mile from his home at 5am by a resident. He was calling out the name of one of the women he had been with earlier.

Fifteen minutes later another neighbour heard Matthew crashing about. She recalled him being fully-clothed but on all fours. Within minutes he vanished from her sight.

Two-and-a-half hours later another resident from the flats, out walking her dog, found Matthew lying face-down on the path behind the flats.

His upper body was naked, with grazes to the elbows. His clothing was strewn nearby. The resident was unable to rouse him and called police.

Two constables arrived at 8.15am and pronounced Matthew dead.

An ambulance crew arrived but was stood down without examining Matthew's body.

A doctor was called to the scene at 9.15am and confirmed Matthew was dead. She said she believed he had been dead for a number of hours.

It was the lack of immediate medical intervention by experts when Matthew's body was found that was to become the focus of a three-year campaign by his mother to get medical experts on to the scene immediately a body is found.

She did not feel comfortable with police officers making medical judgements.

She does not blame the individual officers who found Matthew for assuming he was already dead when they first touched his icy skin but blamed the force for not having a policy where people are assumed to be alive until a medical expert has examined them.

Mrs Shelley said: "I believe in my heart of hearts that Matthew was still alive when they found him."

Matthew died from hypothermia. He had torn his own clothes from his body, a classic symptom as the body goes into spasm.

Mrs Shelley fought a hard but ultimately successful battle to get Sussex Police to introduce a policy instructing officers to assume a person is alive and call medical experts.

She instructed a solicitor, gathered papers from police, the coroner, the ambulance service and even drafted in hypothermia experts to prove there was a possibility her son was alive when he was found. She also had a meeting with a representative from the Police Complaints Authority.

Consultant anaesthetist Dr Lloyd, of Edinburgh, wrote a letter to Mrs Shelley's solicitor saying: "I confirm that, on the information available, my opinion is that, when Matthew was first seen by police, there was a very small chance that it might have been possible to revive him."

Mrs Shelley recruited Brighton MP Des Turner in her battle to have a force-wide policy introduced when dealing with cases such as Matthew's.

More than two years after Matthew's death, Mr Turner received a letter from Sussex Police's discipline and complaints department, saying: "As a result of the inquest into the death of Matthew Shelley in 1997 an amendment was made to the guidance provided to detective officers in the investigation of suspicious deaths.

"This amendment stresses that regardless of the evidence of death, that in all cases ambulance staff and medical experts should be allowed access to the body to provide any assistance they deem appropriate."

In May 2000 Mrs Shelley received assurance from the then chief constable of Sussex Police, Paul Whitehouse, that the policy was then going to be available to all 4,500 police staff, not just detectives.

Mr Whitehouse said in his letter: "It is my hope that you may derive some reassurance from this confirmation of the steps taken by Sussex Police to learn from the events surrounding the death of Matthew."

But after reading an article in The Argus last month about two divers who saved a woman from a river when they had been told to leave her alone by police who thought she was dead, Mrs Shelley fears the policy has been forgotten.

Railway engineers David Kitchen, 23, and Michael Hill, 44, spotted police officers tracking a body that was floating down the River Adur.

Officers had decided not to launch a rescue attempt due to the lack of any signs of life and the perilous conditions.

But after 30 minutes, the woman moved and Mr Kitchen and Mr Hill, who carry out underwater inspections on railway structures, plunged into the water and dragged her out.

Mrs Shelley believes the officers should have assumed the woman floating in the river was alive, rather than dead, although she agrees they should not put their own lives at risk.

She said: "I was so angry when I read the story in The Argus.

"They are assuming there is no hope when they should always assume there is some hope. What has happened to the policy?"

A spokeswoman for Sussex Police said officers did take into account the policy, which came into force following Matthew's death.

She said: "Officers do take the policy into account but every case is dealt with on an individual basis. It is really down to the discretion of an individual officer."

She said in the case of the woman in the river, the two members of the public who went into the river to save the woman had specialist diving equipment with them.