Northern Territory Police appears to have found on Sunday the 62-year-old Australian man who was grabbed by a crocodile while cruising with his family along Kakadu National Park.

However, it was too late because by that time he was already the reptile's meal since they found human remains inside the 4.7-metre crocodile which was shot dead by police.

Police also short another large saltwater crocodile while searching for the man. The crocodiles were then cut open and one of the reptiles yielded a quantity of human remains, although the remains were not yet formally confirmed as that of the missing man, said Northern Territory police sergeant Andrew Hocking.

The human remains were found at midday. The crocodiles were shot in the billabong about 1.5 kilometres from where the man was grabbed. The man, his wife, son and daughter-in-law were in an area of the Kakadu Park recently opened to the public.

They were on a camping holiday and had previously camped at Kakadu, although they are reportedly from Darwin.

When the incident happened, the wife and daughter-in-law drove two hours to the nearest lodge to seek help, while the son stayed behind to search for his father.

Graeme Webb, a crocodile expert, said a crocodile attack at this time of the year is unusual when reptiles usually lay low on cooler months.

Because of the special protection law, introduced in 1971, enjoyed by crocodiles, their number has grown to about 100,000, according to government estimates.