Rangers in Kakadu National Park are scouring waterways for a crocodile that attacked a group of four people fishing at night last weekend.

NT Health has confirmed a 32-year-old New South Wales man was injured after a crocodile – possibly as big as five metres – jumped out of the water into their boat.

“[He] was fishing on the South Alligator river with three friends in a boat on the night of April 24,” an NT Health spokesperson confirmed.

“A crocodile launched into the boat, attacking his seat and injuring the man.”

The Wollongong man and his friends are believed to have stopped on the river to cook dinner onboard when the crocodile attacked.

The victim escaped with minor injuries and was treated at Jabiru Health Centre on Sunday for body grazes.

The NSW suffered minor injuries when the crocodile attacked.

Crocodile expert Adam Britton said crocodiles were capable of launching themselves into boats but said incidents of this kind were “incredibly rare”.

“Big crocs can push themselves out of the water, especially if they’ve got something to rest against like the side of a boat,” he said.

“Apparently, this crocodile actually pushed itself over the gunnels and bit the seat that the guy was sitting in.”

Dr Britton said crocodiles have “very powerful tails, they can dip the tail underneath the water and they can literally push themselves by swimming up out of the water”.

“I mean a five-metre croc can lift itself a good metre and a half, maybe two metres, out of the water and most boat gunnels are not as high as that,” he said.

Dr Britton said judging by the damage to the boat seat and the injury suffered by the victim, estimates it was a five-metre crocodile were not unreasonable.

“It was a pretty big crocodile,” he said.

“In a situation like this if an animal is showing this kind of unusual behaviour then it’s a prime candidate for that animal to be removed.”

The Kakadu National Park crocodile management team is searching for the crocodile.

Dr Britton, who runs a database on crocodile attacks, said the incident takes the number of crocodile attacks in Australia this year to six.

“This is the most attacks since 2017. The last few years have been fairly quiet,” he said.

There was one fatality in north Queensland and three attacks in the Northern Territory.

Kakadu National Park is popular fishing area in the NT.  Photo: ABC News/Sara Everingham

Dr Britton said while crocodile attacks remain rare local fishers should be vigilant, particularly because a good wet season had filled river systems, making it easier for crocodiles to move around.

“It would not surprise me that there’s been more sightings, more call outs and potentially more incidents because there’s greater opportunity for crocodiles to come into contact with people,” he said.

Dr Britton warned night fishers to avoid cooking in boats, saying this could have motivated the crocodile in the Kakadu attack.

In a statement Parks Australia said it was made aware of the incident and said its wildlife operations team was currently searching for the crocodile.

Parks Australia added that it conducts surveys in Kakadu to monitor crocodile numbers and behaviour, and encouraged visitors to be “crocwise” when near Kakadu’s waterways.

-ABC