$1 million police reward now on offer for information relating to 35-year-old cold case

Mark Haines' body was discovered on train tracks outside Tamworth in 1988. No one has ever been charged,.

Mark Haines was just 17-year-old when we was killed and his body discovered by a train driver on the railway tracks outside the NSW town of Tamworth in the early hours of January 16, 1988. Credit: Karen Michelmore, NITV

The family of a Gomeroi man whose suspicious death has never been solved have welcomed a doubling of the police reward for information leading to a breakthrough in the case.

Mark Haines was just 17-years-old when he was discovered by a train conductor in the early hours of January 16, 1988 with only a spot of blood and a towel found under his head.

Police investigators suggested that Mr Haines willingly or accidentally ended up on the railway, but his family have always maintained their belief there was foul play.

Haines' uncle, Don Craigie, said he was "hopeful" the reward's increase would incentivise anyone with information to come forward.

"No matter how minute it may appear, it could be the crucial piece of this puzzle," he told NITV.

"I believe there's only one piece [remaining], and it's almost ready to go into place."

35 years of calling for justice

Uncle Don Craigie believes he is getting close to finding the final piece of the puzzle to solve the heartbreaking mystery of his nephew Mark Haines' death. Credit: Karen Michelmore, NITV

Mr Craigie has tirelessly advocated for another inquest into his Mark's death since the initial investigation in 1989 returned an open finding.

Every year since then, Mr Craigie has journeyed to Tamworth Police Station on the anniversary of his nephew's passing to call for a fresh inquiry.

"For my entire family, we've had pain and suffering all these years. I'm very disappointed in the initial investigations that took place because I daresay so much evidence was lost in those initial investigations."

In February, his efforts were rewarded with the announcement of another coronial inquest into the matter, to be held in 2024.

He dismissed suggestions of personal vindication, saying that he was driven by promises made to his family.

"To Mark's parents and to his grandmother, my mum, I said to all the family, 'You go on with your lives. I'll deal with this.'

"I'm very much encouraged that the information that will be presented in the inquiry will be ... the piece that has been missing for 35 years."