THE parents of an NHS worker who vanished while partying at a nightclub with friends three decades ago believe someone close to her could hold the key to cracking the cold case.

, 25, from , was last seen sitting alone on a stool near the dancefloor in bustling haunt Cadillacs after an argument with her boyfriend in the early hours of June 9, 1996.

NINTCHDBPICT000845971966Hospital worker Melanie Hall disappeared while partying with pals in 1996Credit: Not known, clear with picture desk NINTCHDBPICT001054292800Police released a fresh e-fit image of a key suspect Melanie allegedly left the nightclub withCredit: Avon and Somerset Constabulary

Melanie wouldn’t be found until 2009 when workmen discovered , in undergrowth near a slip road for Junction 14 of the M5 motorway, 30 miles away.

Inside the bags were her partial remains including her skull, pelvis and thigh bone – the rest of the uni graduate’s skeleton, her clothes, bank card, chequebook and several pieces of jewellery have never been recovered.

A post-mortem would reveal Melanie suffered blunt trauma to her head, which resulted in a fractured skull, cheekbone and jaw, but what happened in her final moments is unknown.

Melanie’s dad Steve, mum Pat and sister Dominique have sent out a fresh plea to anyone who may have information about the murder to come forward, the Mirror reported .

They said in a statement: “Despite the passing of nearly 30 years since the disappearance and murder of our daughter Melanie, we remain totally committed to finding her killer.

“Over the years we have worked tirelessly with Avon and Somerset Police to solve this case and are as confident today as we were 30 years ago that her killer[s] will eventually be brought to justice.”

Cops are again asking whether anyone recognises a key suspect in a newly released colour e-fit.

He is described as white, in his mid to late twenties, around 5ft 10ins tall, of medium build, with dark brown hair, dark brown eyes, bushy eyebrows and clean shaven.

The man allegedly left the nightclub with Melanie prior to her disappearance.

Since the , Avon and Somerset have trawled nearly 100 hours of CCTV footage, received 1,700 calls from the public, taken 2,000 statements and interviewed .

A number of theories have emerged since her disappearance – including claims several serial killers, like , may have been involved in her death.

Melanie’s disappearance wasn’t reported until two days after she was last seen when she failed to show up for work.

Her parents believed she had spent the weekend with her boyfriend Philip Kurlbaum at his flat in Bath – but unknown to them, the couple had left Cadillacs nightclub separately.

Philip – who was ruled out as a suspect by – rowed with Melanie that night after spotting her dancing with another man.

The last confirmed sighting was at 1.10am when she was seen sitting alone on a stool near the club’s dancefloor and later one witness claimed to have spotted her with another man.

Detective Superintendent James Riccio said at the time that he believed Melanie left the club with the e-fit suspect and that he was involved with her killing.

He added: “I believe this male was involved in Melanie’s killing. I believe Melanie knew her killer and I believe that male with Melanie had something to do with her killing.

“I believe she knew him, I believe that was Melanie outside and Melanie left with that individual.

“There’s no evidence of an abduction, no evidence of somebody screaming, hence why I believe Melanie knew the individual and left with him.”

Melanie’s remains were discovered in a field close to the northbound slip road at junction 14 of the M5, near Thornbury, in Gloucestershire.

That’s nearly 30 miles away from where she was last seen at Cadillacs nightclub in Bath – it’s still unclear why that spot was chosen.

'I hate not knowing,' says Melanie Hall's sister

THE family have waited nearly 30 years for answers - and so far are yet to be put out of their misery.

In an exclusive interview with The Sun, the sister of Melanie Hall told us that the had caused untold suffering.

Dominique said: “I feel really cross that Mel lost her life and we had ours turned upside down by someone else.

“I wonder if they have any thought or compassion for what they have done, I doubt it.

“I feel incredibly sad for Mel, that she never got to have her life… a career, love, the joy of having children etc.

“I hate not knowing what happened.

“I know she had significant injuries, but I hope and pray that whatever happened it was quick for her, or that there was only one person involved not a gang or something awful like that.

“Obviously, I have no idea what happened to her. All I know is that she was incredibly kind and trusting and I’ve often said that, because of this, she might have trusted the wrong person that night. Almost like her naivety was her own demise.”

Even Det Supt Riccio noted: “It’s quite an odd place to dump a body.”

Due to being such an obscure location, he believes it’s “highly likely” the person was familiar with the area – meaning they may be local to .

Det Supt Riccio has previously emphasized that the person who disposed of Melanie’s body may not have killed her.

The decision to leave her body somewhere so remote, where she would go undiscovered for more than a decade, could also suggest the individual was a professional.

Professor Monckton-Smith said: “What a place to leave a body, in some ways a really good place, because, a slip road, on the motorway, you’re not getting your usual dog walkers and your joggers coming past.

“Which I think is why Melanie’s body lay where it did for so long. It was more than likely a deposition site.

“The murder and murder scene is somewhere else that the police still don’t know. I think that whoever left Melanie’s body, was at least familiar with that area.”

The case remains active and Det Supt Riccio, who has spent years investigating it, believes “one small piece of evidence” is all they need.

He said he suspected someone was covering for the killer and held vital information that could crack the case.

Det Supt Riccio said: “In Bath, there is someone who holds a dark secret. Whether that’s whoever killed Melanie or knows who killed Melanie – and we need those people to come forward.

“Somebody killed Melanie, someone disposed of Melanie and that may have been one or two individuals.

“But someone would have said something, someone would have been acting suspiciously, someone would have broken away from their group that evening watching the football and then continued on their own elsewhere.

“Someone may be acting suspiciously every time Melanie’s name is mentioned. Those little snippets are what we need someone to come forwards and tell us.

“I still strongly believe that somebody knows what happened to Melanie and somebody will watch this documentary and look at the anguish the family are facing every single day.

“Do it for them, come forwards. We can protect you, give us that information and we will bring the killer of Melanie Hall to justice.”

Melanie Hall deathMelanie Hall’s body was discovered in 2009Credit: PA Melanie Hall murderPolice forensic officers sifting and checking soil near where Melanie’s body was foundCredit: PA:Press Association Melanie Hall murderMelanie vanished while partying at Cadillacs nightclub in BathCredit: PA:Press Association