Triple murderer Max Sica has launched a fresh bid to clear his name.

Lawyers will be relying on new evidence to unravel one of the biggest criminal cases in Queensland’s history.

Neelma Singh and her siblings Kunal and Sidhi were murdered in cold blood in their Bridgeman Downs home, in Brisbane’s north, in 2003.

Their convicted killer, Sica, was Neelma’s boyfriend at the time and has spent 16 years in jail for their murders.

Sica was on police’s radar from the start, telling detectives he discovered the trio’s bodies in the bathtub.

But it took almost a decade before a jury found him guilty and handed him a record 35-year sentence.

Now, Sica’s legal team is launching a fresh appeal on the grounds new or compelling evidence has been uncovered.

“It’s got to be evidence that was not reasonably available either to the defence or to the prosecution at the time of the first trial,” criminal lawyer Bill Potts told 9News.

Former detective Graham Crowley has examined the Singh murders in detail in his podcast, Loose Ends, and believes an innocent man could be behind bars.

“Let me put it this way: the evidence doesn’t show that Max Sica did those murders,” he said.

He believes there’s questions specifically surrounding some of the footprints police collected and how the murder weapon was discovered.

This week marks 22 years since the gruesome murders and each of the families involved are living a life sentence.

Sica’s parents have always maintained their son’s innocence, telling 9News the appeal should be granted.

The paperwork is expected to be formally lodged next week, with a hearing later this year.