Rodeos could be against the law if it was not for a specially written set of standards, a senior government animal welfare investigator has said.
An internal MPI document from 2015 obtained under the Official Information Act quotes the unnamed investigator saying that rodeos could be "problematic and prosecutable" if the Rodeo Code of Welfare did not exist.
The code sets minimum standards that those involved with rodeos should aim for, but they are goals and breaching it does not constitute a crime.
In the memo, the investigator listed 18 points they used to approach allegations of animal mistreatment, including that they believed the code "statutorily reduces the threshold, scale, impact and severity" of the Animal Welfare Act.
The Animal Welfare Act sets the rules for the treatment of animals.
The investigator also said the code's minimum standards acted "as a shield to protect a defendant in the face of a prosecution".
MPI's director of animals and animal products, Paul Dansted, confirmed that someone alleged to have mistreated an animal at a rodeo could defend themselves by showing they equalled or exceeded the minimum standard in the code.
But he said that the various codes of welfare did not protect those who breached the Animal Welfare Act in any way.
The code for rodeos stipulates that "rodeos involve situations where animals are subjected to a risk of injuries and distress".
Animal welfare lawyer, vet and former MPI prosecutor Ian Robertson said the code might not reflect current best practice.
"Our ideas and concepts and what we consider acceptable in terms of animal treatment change with time," Mr Robertson said.
"There may be certain practices or events that good practice and scientific knowledge would say, perhaps it's timely we review those.
"The codes themselves, while a great concept and obviously important, there's been criticism that they're not keeping up."
Rodeo Cowboys Association 'happy with the way things are'
Rodeo Cowboys Association spokesperson Michael Laws said the association complied with its legal obligations.
"All the practices that are associated with rodeo have been independently scientifically verified, investigated, and condoned by Parliament," Mr Laws said.
"If Parliament at one stage wants to change its views, we'll actually have that discussion and that debate, and we'll abide by what they come by.
"But at the moment we're happy with the way things are. We think they represent the best practice."
The SPCA, SAFE, and other animal welfare organisations have called for rodeos to be banned.
The Veterinary Association has said it wants the rodeo code to be reviewed. It has to be updated every 10 years and this was last done in 2014.