Charges are being brought against winner Gino D'Acampo and fellow contestant Stuart Manning after the chef apparently killed and butchered a rat to add meat to a meal.
The animal may have been a tame rat let loose on the set to add drama, rather than the wild variety.
During the series the contestants were divided into two groups, one of which was in "exile" with meagre rations.
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As the celebrities became concerned that they would lack the energy to complete physical challenges, D'Acampo, 33, decided to take matters into his own hands.
He said in the show's video diary room the Bush Telegraph: "It's not done by choice but it's done because we need it. We need some kind of protein, we need some kind of flavour.
"I saw one of these rats running around. I got a knife, I got its throat, I picked it up."
The group, including 30-year-old Manning, ate the rat and enjoyed the meal.
Fellow contestant George Hamilton spoke out in defence of his former camp-mates, saying ITV producers had given them permission to eat the rodent.
The actor said: "When Lucy (Benjamin) saw a rat Gino said, 'We've got to get that'.
"So I went into the Bush Telegraph and said, 'May we eat a rat?' They were a bit shocked, thought about it and then said we could. It was a very good dinner."
Ch Insp David Oshannessy from the RSPCA in New South Wales, said it was not acceptable that an animal had been killed as part of a performance.
He said: "The allegation is that an animal was cruelly treated on the set. It was a rat that was killed. There is a code of conduct in New South Wales that dictates how animals can be used. The killing of a rat for a performance is not acceptable."
The charity sends staff whenever animals are used for filmed or live performances, he said, and so had been in contact with the programme's producers before the rat was killed.
A spokeswoman for New South Wales Police said there were currently no plans to bring charges against the show producers.
The force's statement about the two men read: "Police from Murwillumbah yesterday issued field court attendance notices to two men aged 30 and 33 for the offence of animal cruelty. They are due to attend court at Murwillumbah local court on February 3, 2010."
Chef Antony Worrall Thompson, who appeared on I'm a Celebrity in 2003, said the show's producers should take some responsibility for the incident.
He said an announcement was made warning him not to kill spiders because they were a protected species while he was in the camp.
"Maybe the producers are at fault for not warning them," he told Sky News.
"Personally, I would be looking further up the field."
Broadcaster ITV issued a brief statement which said: "The New South Wales RSPCA are currently looking into an incident in which a rat was killed in the camp."