The possibility of new mass greyhound graves in New South Wales has prompted the state's racing body to appoint a forensic investigator.

Greyhound Racing NSW has asked forensic firm KordaMentha to investigate new information concerning more possible greyhound grave sites across the state.

This includes fresh allegations of a mass grave in the vicinity of a former greyhound racing track.

A report on the Keinbah Trail Track by senior barrister Clive Steirn found up to 99 greyhounds had been killed and buried at a Hunter Valley training track between 2009 and 2013.

NSW Premier Mike Baird announced his decision to ban greyhound racing following the release of a special commission report into the practice, which found overwhelming evidence of animal cruelty, including mass killings and live baiting.

He has stood by the decision, despite it being labelled as class warfare and Nationals MPs threatening to cross the floor over the move.

Paul Newson, the interim chief executive of Greyhound Racing NSW, said the Keinbah report revealed that witnesses misled the previous inquiry.

"I've briefed KordaMentha to review the investigations we had previously undertaken, and with new information that is coming to hand see what additional avenues of investigation they can take up," Mr Newson said.

At least 99 greyhounds were brutally killed and buried at a site in the Hunter Valley. ( Supplied: Mike Baird, Facebook )

"Obviously the Keinbah report has sparked some interest in the public, has caused some members of the community to call in, to write in and provide us with information which suggests there may be additional grave sites out there.

"We need to test the substance, we need to test the veracity of these reports."

Mr Newson said, in his opinion, it was not up to Greyhound Racing NSW to contest the Government's decision to ban the sport.

"We are the regulator, we are responsible for effectively supervising the industry and as well we are responsible for the commercial activities of that industry," he said.

"We need to continue to supervise the industry in a transparent manner ... so we need to insure that if there is a suggestion that witnesses have mislead our inquiry we need to resolve that.

"If there is a suggestion that there have been further incidents of shocking animal cruelty we need to resolve that."

Report that led to ban factually flawed: greyhound industry

The NSW greyhound racing industry has launched a challenge in the NSW Supreme Court against the report that led to the Baird Government's ban on the sector.

The industry said the report was unreasonable and went beyond its scope, and wanted it declared invalid and of no legal effect.

Brenton Scott, chief executive of the Greyhound Breeders and Trainers Association, said the group was challenging the overall validity of the report.

"The proposed ban ... is based on information in the report, the report suggests that the greyhounds industry has lost its social licence, an intangible concept and one that we would argue in no shape or form have we lost," he said.

"The report is factually flawed, we believe we will challenge that very completely in the proceedings.

"Our action in the overall sense is evidence of the industry's commitment to getting a fair go is absolutely completely.

"The structure, the intent of the report, it's almost preconceived structure, really did not provide the industry with the proper level of procedural fairness that it have provided."

Mr Scott said if there were any people misleading any investigations into the treatment of greyhounds they needed to be held to account.

"Greyhound racing needs to confront any of its issues, [and it] needs to do that openly and transparently," he added.

"We need to establish in that process ... [find] where the bad apples are, rid this industry of that component and allow the industry to continue for the vast majority of good people, who are doing ... the right thing by the people of NSW and deserve to be given a fair go."