Prisoners have allegedly been killing and eating guinea pigs taken during their supervised work at a Perth animal shelter.

The male inmates allegedly involved were part of the Section 95 work release program at the minimum-security Wooroloo Prison Farm, which allows approved prisoners to work on projects out in the community.

Corrective Services Commissioner Brad Royce said the alarm was raised after a prison staff member found guinea pig carcasses stored at a shed outside the prison borders.

”They didn’t get them into the prison, they have an external area where we maintain tool sheds, things like that for working in the community,” he told Nine radio’s 6PR Breakfast.

Royce said the allegations raised security concerns, as the Section 95 prisoners are discouraged from eating off-site.

“In this case, there was a deal done, obviously. That will come out in the investigation,” he said..

“The issue for me isn’t so much the guinea pigs, as bad as that sounds, it’s more about the security and making sure that we follow the rules and keep everyone safe.”

Royce has ordered an investigation into what he said were disturbing allegations.

All Section 95 programs have been suspended pending the outcome of the investigation.

Wooroloo Prison Farm is a male prison in outer Perth, about 55km north-east of the CBD.

The prison has been operating the Section 95 program since 1998 to provide essential services to local communities.

Under Department of Justice policies, prisoners working in the program are not allowed to receive any goods or bring back any goods to the prison without approval.