Police have found the remains of a 12-year-old girl, two days after she was snatched by a crocodile while swimming in a creek in remote northern Australia.

The remains were found in the river system near where the girl vanished at the Indigenous community of Palumpa, south-west of the Northern Territory capital Darwin, Police senior Sgt Erica Gibson said.

Injuries confirmed a crocodile attack, Sgt Gibson said.

“The recovery has been made. It was particularly gruesome and a sad, devastating outcome,” she told reporters.

Efforts were continuing to trap the killer crocodile, she said. Saltwater crocodiles are territorial and the killer is likely to remain in nearby waterways.

The girl’s disappearance triggered an intense 36-hour land, water and air search.

The crocodile population has exploded across the country’s tropical north since they became a protected species under Australian law in 1970s.

Because saltwater crocodiles can live up to 70 years and grow throughout their lives – reaching up to seven metres (23ft) in length – the proportion of large crocodiles is also rising.

Crocodiles are considered a risk in most of the Northern Territory’s waterways.