Three Victorian greyhound trainers have been suspended after allegedly using possums as live bait, but the head of the sport insists the illegal practice is not widespread.

Key points: Animal cruelty charges are expected to be laid against three greyhound trainers

Animal cruelty charges are expected to be laid against three greyhound trainers The unnamed trainers are alleged to have used live possums to "blood" greyhounds

The unnamed trainers are alleged to have used live possums to "blood" greyhounds Greyhound Racing Victoria says most trainers are doing the "right thing"

Greyhound Racing Victoria (GRV) and the RSPCA are continuing to investigate the matter and are expecting to lay animal cruelty charges.

"We haven't laid charges yet. They are suspended. The next step is to put together what we've found and basically chase this matter down to its fullest extent," GRV chief executive Alan Clayton told ABC Radio Melbourne.

Mr Clayton would not reveal the names of the trainers involved or how they were caught.

"We found the matter using our intel capability. We've got a combination of intel, analysts, covert [workers], and we use all of that and more in the context of the work that we do."

The stood-down trainers have now been banned from entering any greyhound property or clubs.

If found guilty, they face life bans from the sport and criminal convictions.

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Live baiting 'completely unacceptable': minister

Mr Clayton said it was "abhorrent" if trainers used animals on lures, a practice known as "blooding" that often resulted in dogs mauling them to death.

"Most greyhound trainers are actually doing the right thing and they're using synthetic lures," he said.

"We've promoted an ethical industry, we've increased our capability in integrity and animal welfare."

Victorian Racing Minister Martin Pakula said he was encouraged that racing integrity officials had discovered the alleged cruelty, instead of the tip-off coming from activists or journalists.

"The test is can you detect them, can you catch them, can you charge them and can you rub them out?" he said.

"I don't think five years ago greyhound racing had the capacity to do those things. Now it does.

"If the allegations are right, it's cheating in the form of cruelty to animals. It's completely unacceptable."

'Where there's money involved, people will try to cheat'

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The suspensions come four years after the national greyhound racing industry was rocked by an animal cruelty scandal, with trainers exposed for using live rabbits and pigs used as lures.

Dozens of trainers were caught up in the scandal and industry-wide reforms were promised by the sport's organisers.

The NSW Government announced a ban of greyhound racing in the state in 2016, but reversed its decision four months later after sustained pressure from the racing industry and its supporters.

Julia Cockram, from the Coalition for the Protection of Greyhounds, said blooding increased dogs' "prey drive" and made them race faster.

"I'm not surprised at all that it's happening behind closed doors," she told ABC Radio Melbourne.

"I'm pretty sure its much more widespread than three individuals in the industry."

Mr Clayton said he did not believe the method worked, but acknowledged: "in any industry or sport where there's money involved, people will try to cheat".

He said the greyhound industry was committed to the welfare of the animals, including re-homing them after their racing careers ended.