Story highlights Man, 62, killed by crocodile in remote Australia

Police shoot two animals, find human remains in one measuring 15.5 feet

Expert says crocodile attacks are unusual at this time of year

Second deadly crocodile attack in Kakadu in 2014

Authorities have recovered human remains from a large crocodile that's believed to have taken a man from his boat in Australia's remote north.

Rangers shot dead two saltwater crocodiles in the Northern Territory's Kakadu National Park on Sunday after searching through the night for a 62-year-old man who was reportedly snatched at a waterhole on the South Alligator River the previous afternoon.

One of the crocodiles, measuring around 15.5 feet (4.7 meters), contained human remains, police told reporters Sunday. A statement on the Northern Territory Police Force Facebook page said the victim's body had been recovered and a report would be prepared for the Coroner.

The man had been fishing with his son, wife and daughter-in-law when the incident occurred, Northern Territory Police Sgt. Andrew Hocking said. The victim's family witnessed the attack but were unable to save him.

With poor cellphone coverage across large parts of the remote region, the man's wife and daughter-in-law drove two hours to alert authorities to the attack, according to the Northern Territory News.

Police and park rangers searched the area with a helicopter and boats over the weekend, and found two large crocodiles about a mile (1.5 kilometers) from where the man was last seen, according to Hocking.

Police have not released the victim's name.

"This is a tragic event and our thoughts are with the family during this very difficult time," said Commander Bruce Porter of the Northern Command.

A crocodile expert, Grahame Webb, said it was unusual for the reptiles to attack at this time of year as they are rarely active during the cooler months, local media reported

"They tend to move around a lot more when it warms up... and that's when they're more dangerous," he said.

The crocodile-infested waters of Kakadu National Park make it a notoriously hazardous area for humans. But most attacks involve swimmers, not people on boats, according to a study in the Wilderness & Environmental Medicine journal.