A pet cat was stuffed in a backpack and drowned in a "disturbing" act of cruelty during the recent South Australian floods, the RSPCA says.
The drowned cat was found in a bag spotted floating in the Munno Para Wetlands, north of Adelaide, by a passerby on October 2.
The female tortoiseshell cat, which had a light-blue collar, was taken to a local vet, who alerted the RSPCA.
"This is a really disturbing act of cruelty," RSPCA SA chief inspector Andrea Lewis said on Monday.
"To deliberately place an animal in a situation it can't escape from and then drown it - it's terrible."
She said it could be plausible the cat was put in the backpack by someone trying to escape the floods, but this was unlikely.
"There might be some magical explanation for why the cat was in there but cats can't get in there themselves."
Ms Lewis said the cat was not microchipped but appeared well looked after and was clearly someone's pet.
The person responsible could face a prison sentence if caught and convicted of animal cruelty.
RSPCA SA originally said the backpack was found in the Gawler River but revised the location after speaking with the person who allegedly found the bag.
Anyone with information should call RSPCA SA's cruelty line on 1300 477 722.
