COLD-CASE detectives, who spent the past five years re-investigating an unsolved murder, have been forced to admit defeat after exhausting all lines of inquiry.

The Swansea sex shop murder happened during a busy Friday lunchtime on June 14, 1985.

While pedestrians, buses and cars passed by outside the Private Shop in Dillwyn Street opposite Swansea’s Grand Theatre, the shop’s manageress, mother of four Sandra Phillips, 38, was raped and beaten to death.

Her body was discovered by area manager Anthony Williams who called at the store just before 2pm and found it closed. When he unlocked the door using spare keys he found Mrs Phillips in a pool of blood.

Neath brothers Wayne and Paul Darvell were arrested soon after the killing, and a year later they were jailed for life for the murder.

But, after a BBC Rough Justice programme highlighted Wayne Darvell’s habit of confessing to crimes he had not committed, the brothers were freed.

The pair, who had spent seven years in jail, were each given £80,000 in compensation, Paul Darvell dying of natural causes three years ago while Wayne Darvell is believed to be still living rough.

Police subsequently reopened the case, but it now appears that the true killer may never be found.

South Wales Police said yesterday despite taking down walls inside the Private Shop to take DNA samples and re-interviewing some of the 200 men who had been members of the shop’s blue movie club, there is still no prospect of anyone being charged.

A spokesman said: “All lines of inquiry and forensic opportunities relating to this case have been exhausted.

“Members of Sandra Phillips’ family and an Independent Advisory Group, which was set up during the original review to overlook the inquiry, have been updated on these developments.

“The force has also apologised to the family for the shortcomings of the original investigation conducted in 1985 into the tragic murder of Sandra and for the distress that this has caused them.

“The Force however has remained fully committed in attempting to bring those responsible for her murder to justice and had commissioned an independent review and a full re-investigation but sadly, despite those efforts, those responsible for her death have not been identified.

“Since 1985 there have been significant changes in the way serious criminal offences are investigated and reviewed by the Force.”

Detective Superintendent Paul Burke added: “It is important to stress an investigation is never completely closed and any new information which is received will be fully investigated and the inquiry will be revisited periodically.

“This news will obviously be upsetting for Sandra Phillips’ family and come as a disappointment for the Swansea community.

“We would like to thank those people who responded to our previous appeals and thank the media for their continued support in this investigation.”

At the time of the Swansea sex shop murder Sandra Phillips’s second husband Peter was working as a manager at the Co-op Store in Oxford Street, Swansea, just a few hundred yards away.

He was informed by police of what had happened soon after her body was discovered and he had the grim task of telling their children their mother would not be coming home.

One of them, Elizabeth Grace, was 14 on the day of the murder and her mother had dropped her off at a local school before driving on to work. Mrs Phillips had not wanted to take the job at the sex shop but financial pressures meant she had to find work.

When the cold case investigation began in 2004, Ms Grace, who was then 34, bravely made an appeal on the BBC’s flagship Crimewatch programme.

She said at the time, “It’s now been 20 years and I’d like whoever did it to not be walking around having his life.

“Catching whoever did it won’t bring mum back, but I want them to realise what they’ve done, not just to myself but also to my family’s next generation.”