Two Australian men may be prosecuted after they chewed live mice and bit off their tails as part of a pub competition to win a holiday.
The RSPCA called the incident "outrageous" and said it would seek the maximum penalty against the men.
RSPCA chief inspector Byron Hall said they could face two years in prison and fines of A$75,000 (US$52,050).
The Brisbane hotel where the contest took place condemned it and said it would not happen again.
Mr Hall said both men put mice in their mouths and bit off their tails. One of the men went on to further chew his mouse then spat it out.
They were taking part in a "Jackass promotion" - named after a US TV stunt show - which took place on Wednesdays at the Exchange Hotel in Brisbane and involved undertaking dares, one of the hotel's managers told BBC News Online.
It was not clear who organised the promotions, but Marie Middleton said they had now been stopped.
"The whole incident was horrific," said Ms Middleton.
"It was all supposed to be harmless fun," she said, adding that the hotel had now "tightened management procedures 100%".
She said the hotel was assisting the RSPCA (Royal Society for the Prevention of Cruelty to Animals) in their investigations.
A Queensland state minister, Henry Palaszczuk, urged anyone with information to contact the RSPCA.
The winner is still being sought, while the other competitor has already been interviewed.
"Chewing a mouse and spitting it out is not entertainment, it is barbaric," said Mr Palaszczuk.
"All animals deserve respect. How we treat animals is a measure of how civilized our society is," he said.