Human remains have been found inside a crocodile close to where a man disappeared from his boat in Australia's Northern Territory on Saturday.

Police found the remains inside a 4.7-metre (15ft 5in) saltwater crocodile that was shot by park rangers searching for the 62-year-old man who was attacked in Kakadu National Park, south-east Darwin.

Authorities said the man was snatched while emptying a bucket over the side of his boat. The remains are now being examined to see if they match the man's DNA.

Northern Territory police sergeant Andrew Hocking said the crocodile was one of two that were shot about 1.6km (1 mile) from the site of the attack.

"There are a number of statements to be taken from witnesses and a file will be prepared for the coroner," Hocking told ABC News.

"The difficulty in this location is getting in large boats. We're only able to bring in small boats, but using the expertise of the Territory Parks and Wildlife staff, they managed to help us bring it to a conclusion. Thankfully this was carried out and [the victim] recovered very, very quickly."

Hocking urged visitors to exercise caution when visiting the area, as there is "always the potential for an attack".

Crocodile expert Graeme Webb said crocodile attacks are unusual in Australia at this time of year.

"Attacks usually occur in the warmer months of the year when the crocs are more active and they need more food, so it's unusual to have an attack like this at this time of year," he said.

"They are serious predators and people need to always treat them seriously."

The attack is the second fatality involving a crocodile to occur in Kakadu this year. In January, a 12-year-old boy was killed and his friend mauled by a crocodile as they swam in a water hole in the park.

The number of crocodiles in Australia's tropical north has risen since the animals were protected by federal law in 1971.