Police in Northern Territory had notified local authorities about a crocodile that was terrorising the local population along a beach near the community of Galiwinku.
The rangers who went to the area yesterday, saw the 3.5 metre reptile grabbing a dog by the leg, and they shot it.
"Out there yesterday afternoon, the crocodile spotted a dog on the beach and started going towards the beach, in the direction of the dog," the ABC news quoted the Northern Watch Commander Greg Pusterla as saying.
"Fortunately someone called the dog away and the croc then retreated back out into the water." the ranger added.
Saltwater crocodiles are a common feature of Australia's tropical north. They can grow up to seven metres long and weigh more than a tonne. These reptiles are known to kill an average of two people a year.