Qld cops confident of solving cold case

A teenage girl who was just four when her mother and uncle died in a suspected 2004 double murder in north Brisbane is helping homicide detectives to solve the cold case.

Siblings April and Ian Bailey were found dead in their Deception Bay home in May 2004 after it was destroyed by fire.

April's four-year-old daughter, now a high school student, was found uninjured at the scene.

Forensic investigations have already revealed the pair had been killed before the fire was lit and one triple zero phone call is believed to have captured Mr Bailey screaming.

Homicide investigators revealed on Monday they had begun a review of the cold case and were using advanced forensic and scientific processes to examine evidence.

Detective Inspector Damien Hansen said a number of people, including April's daughter, were assisting investigators.

"I'm very confident with the progress of the case that we'll get a positive outcome," he said.

He wouldn't reveal whether there were any suspects or how the pair died.

Voice identification processes are being used to examine two of the three triple zero calls made around the time of the fire, including one that is believed to have been from a phone accessed by April's daughter and includes an argument in the background.

A military knife and matching scabbard located at the scene are also being looked at.

"DNA has advanced tremendously and the ways of identifying it, locating it ... have improved enormously over the last 10-12 years," Det Insp Hansen said.

He said it was possible more than one person was responsible for the suspected killings and several people had already provided anonymous tip-offs to police in relation to the deaths.

There is a $250,000 reward for information leading to the apprehension and conviction of those responsible for the murders and arson.

Police said indemnity from prosecution would be recommended for any accomplice, not believed to have been the offender, who provided information.