More than a dozen mutilated animals including a decapitated koala, dogs, birds and possums, have been discovered in an inner city Brisbane park.
Horrified council workers made the macabre discovery at Toowong's Anzac Park in the heart of the city on Thursday night.
Two 44-litre drums containing soil were found at the scene, with the mutilated animal corpses placed in a pile nearby.
"Officers were called to a location on Wool Street around 6.30pm after the animals, including koalas and dogs, were discovered on a grass verge," police told AAP in a statement.
"Investigations are underway into the cause of death and the circumstances leading up to them being left."
Brisbane's Lord Mayor Adrian Schrinner said it was a "sick act" and the officers who stumbled on the gruesome scene had been offered counselling.
"I'm saddened, disturbed and appalled at what's occurred here," Cr Schrinner said.
"It's now a matter for police who I hope will find the culprits so our courts can deal with them."
Police and the RSPCA have launched a joint investigation and will scour the city's network of CCTV footage but have asked anyone with information to contact authorities.