A grief-stricken family has been left shattered after a request for a second inquest into the 1989 bludgeoning death of 15-year-old Annette Mason in a Toowoomba share house was rejected.

The request comes following an initial inquest in the early 90s, which – despite hearing from 25 witnesses – failed to identify anyone responsible.

Queensland’s Attorney-General Yvette D’Ath rejected the request for a second inquest, due to the absence of “fresh and compelling evidence”.

Criminal lawyer and director of law firm Potts Lawyers Bill Potts said that while “more than just a mere suspicion” was required to warrant a second inquest, he believes the case deserves further consideration.

“I think there is a lot she [the attorney-general] hasn't heard and if she had met with the family she might have found out a lot,” he told 9NEWS.

Annette’s sister Linda said the denial of her family’s request has left her “shocked beyond belief”.

“The onus is now back on the police to do something or for someone to come forward with information,” she said.

Police suspect a group of well-known criminals who were with Annette the night of her death could have been responsible for her death.

Annette’s family is hopeful one of their associates might come forward to give evidence.

“It would mean the world,” Linda Mason said.

“Twenty-seven years is a long time to not know what happened.

“Just having closure would be the best thing.”