A man who murdered a teenage babysitter could be offered immunity if he gives up information on the whereabouts of two other women he has long been suspected of killing.

Derek Sam is serving a life sentence for the murder of 16-year-old Queensland girl Jessica Gaudie in 1999.

Police suspect he is also linked to the disappearances of British backpacker Celena Bridge and teacher's aide Sabrina Glassop who vanished decades ago, The Courier Mail reported.

Neither of the victim's bodies have been found - despite repeated searches in the forest surrounding Kenilworth, in the Sunshine Coast, where officers believe their remains are buried.

Derek Sam has been serving time in jail over the 1999 murder of 16-year-old Queensland teenager Jessica Gaudie

None of the victim's bodies have been found - despite repeated searches in the forest surrounding Kenilworth, in the Sunshine Coast, where officers believe the remains are buried (pictured, Jessica Gaudie)

Sam has already served the minimum parole period of his life sentence over the murder of Ms Gaudie.

She had been babysitting his children at their Nambour home, in south-east Queensland, at the time she went missing.

Sam claimed he had picked her up and driven her to a party, though she didn't show up.

Although he has denied the murder, a jury found him guilty and he was jailed for life.

Sam was eligible for parole in 2016, but has been kept behind bars because of a 'no bodies, no parole' law.

Police believe that Sam has refused to give authorities the location of the body of Ms Gaudie as it will lead to the discovery of the other two women.

Detectives are currently building a brief to submit to the Department of Public Prosecutions as they attempt to bring two murder charges against Sam.

Though as they build their case, they are understood to be considering an alternative deal.

In exchange for information on the whereabouts of the bodies, they may be prepared to drop the two murder charges.

Ms Bridge was hiking to Little Yabba Creek camping ground at Kenilworth before she went missing in July 1998.

She was last seen walking along Booloumba Creek Road.

Ms Glassop disappeared in May 1999, after her car was found parked at Little Yabba Creek, a short distance from her home.

Queensland detectives have consulted the New South Wales team that worked on Matthew Leveson's case as they consider offering Sam immunity.

Ms Bridge was hiking to Little Yabba Creek camping ground at Kenilworth before she went missing in July 1998

Ms Glassop disappeared in May 1999, after her car was found parked at Little Yabba Creek, a short distance from her home

Mr Leveson was last seen leaving a Sydney nightclub on September 23, 2007.

His boyfriend Michael Peter Atkins was initially arrested in 2008 though acquitted of murder by a jury in 2009.

Atkins was eventually given immunity in exchange for information on the location of the 20-year-old's body.

The skeletal remains of Mr Leveson were eventually uncovered at the Royal National Park in May 2017.

His mother Faye Leveson admitted she was hesitant to accept the proposition when police approached her with the idea of offering the suspected murderer immunity for information on her son's whereabouts.

'And to me, to bring Matty home, not to be discarded like a piece of rubbish like he was, was the most important thing a mother could do.

'You don’t want to know that your son or your daughter’s out there.'

Tammy Jensen said finding the body of her teenage sister Ms Gaudie would add closure, but she would not accept it if it meant Sam was released from prison

She said she feared she would never have gotten her young boy's body back and that the trauma would haunt his two brothers.

'We didn’t want to leave this for them and for them to worry where their brother is.'

Bosscher Criminal Lawyers' Grace Townsend said handing out immunity was rare.

While the suspected murderer might escape a guilty verdict, Ms Townsend said some closure could be gained from locating the bodies of the women.

Despite this, the families of the three victims have shown concern over the idea of Sam walking free.

Tammy Jensen said finding the body of her teenage sister Ms Gaudie would add closure, but she would not accept it if it meant Sam was released from prison.