A Queensland tourist has received medical treatment after being bitten by a freshwater crocodile at a popular Northern Territory waterfall.

The 36-year-old tourist was at Wangi Falls in the world-renowned Litchfield National Park, about 100 kilometres south of Darwin, when he decided to go for a swim about 7pm Wednesday.

Duty Superintendent with NT Police Bob Rennie said the man felt a bite on the calf of his leg.

“He looked down and he had a baby croc hanging off him,” he said.

“He’s wedged the jaws open and got it out and this little croc has given him a little shake and bitten him on the finger as well.”

He dressed the wound himself, but went to the nearby Batchelor Health Clinic for further help.

“He ended up with two stitches in his finger and eight staples in his leg,” Mr Rennie said.

Police intend to talk with authorities from the park today about the incident, and a ranger has told ABC Local Radio Darwin that a decision had been made to close the falls to swimming.

Freshwater crocodiles are not as dangerous as saltwater crocodiles and usually eat small prey like lizards, frogs, fish and insects.

“We’ve had little freshies in a lot of our swimming holes in the Territory for many, many years and 99 per cent of the time they don’t have a go at you, so maybe this little croc was spooked,” Mr Rennie said.

But it is not the first time a freshwater crocodile has bitten a someone at Wangi Falls.

Two years ago, two people were bitten at the falls in separate incidents when a one-metre crocodile caused trouble for swimmers.

Anne Cameron, 79, was reported missing in Port Douglas last week. Photo: ABC

The attack comes just days after human remains were found in a 4.3-metre crocodile responsible for taking a grandmother in far north Queensland.

Anne Cameron, 79, disappeared from aged care facility Ozcare near Port Douglas on October 9 after she went for a walk.

Police and SES crews later made a grisly discovery of human remains, jewellery and Ms Cameron’s walking stick on the banks of a creek inlet near the Mowbray River, north of Cairns.

Wildlife officers found and killed a crocodile in the Mowbray River system on Tuesday.

Human remains and a number of items which belonged to Ms Cameron were found in the animal, which has been euthanised.

– With ABC