How the gruesome cold case murder of a Sydney horse trainer could finally be solved after disturbing new information emerged about a 'ring in' betting coup 36 years on

The 36-year-old cold case of a Sydney race horse trainer is one step closer to being solved after a tip off about a 'ring-in' betting coup.

The body of George Brown, 38, was found inside a burnt-out Ford Falcon in bush land at Bulli Tops, north of Wollongong on April 2, 1984.

Mr Brown died from head injuries inflicted prior to the sedan being set on fire with his body inside. His legs were broken and his arm was bent backwards.

Detectives now believe Mr Brown was murdered by someone in the racing industry because he didn't want to be involved in a 'ring-in' at a race meeting in Brisbane a month before his death, The Daily Telegraph reports.

The body of George Brown, 38, was found inside a burnt-out Ford Falcon in bushland at Bulli Tops, north of Wollongong on April 2, 1984

Detectives now believe Mr Brown was murdered by someone in the racing industry because he didn't want to be involved in a 'ring-in' at a race meeting in Brisbane a month before his death

Mr Brown died from head injuries inflicted prior to the sedan being set on fire with his body inside the car . His legs were broken and his arm was bent backwards

'That is a strong line of inquiry, although not the only one,' Detective Sergeant Steven Morgan said.

Several people came forward with information after NSW Police offered a $1million reward in April last year.

'After the reward quite a few people have contacted us, some have been discounted but there are a few we believe have information that is credible and worth further investigation,' Sergeant Morgan said.

'Some have given statements, while others have spoken to us but don't want to make a formal statement for a variety of reasons, including possibly fear or believe what they have heard is purely rumour.' 

Mr Brown's sister Jean O'Leary said she had a close relationship with him and helped raise him after their mother died.

'George was a good man and his death has impacted our entire family,' she said last year. 

Mr Brown worked at the Randwick racecourse in Sydney

'Every year since he was murdered, I have hoped that someone would come forward because it's the right thing to do.'  

Mr Brown worked at Randwick racecourse in Sydney.

His killing had been linked to the Fine Cotton scam, a scheme which involved a faster racehorse being disguised as a slower one.

During the inquest, the murder was also linked to the poor performance of one his horses, the Illawarra Mercury reported.

In 2016, Mrs O'Leary said she did not know why her brother had been 'absolutely mutilated'.

'You never get over it, it's with you every day - the torture, the absolute torture that such a good man would have died like that,' she told the Illawarra Mercury.  

'He wasn't a rogue, he wasn't dishonest. Who would want to do it to him, I wouldn't ever know.'