A Newcastle doctor who was snatched by a crocodile after slipping into the river performed a final brave act to save his wife’s life before he vanished.

News.com.au journalist Alexis Carey reports that her brother-in-law David Hogbin was the victim of the fatal crocodile attack in far north Queensland on Saturday.

The remains of the missing 40-year-old father are believed to have been found within a huge 4.9-metre reptile that was captured on Monday and euthanised.

The general practice doctor had been on an incredible trip with Jane, their three young sons – aged seven, five and two – and Jane’s family on a 4WD and camping holiday.

“Contrary to initial reports, he was not fishing at the time,” wrote Carey.

“While walking along an established path on a 15-metre high riverbank – well out of a crocodile’s striking range – it is believed a portion of the bank suddenly gave way, perhaps due to recent heavy rainfall in the area.

“It caused Dave to fall down into the river below, and despite being tall, strong and fit, the conditions of the terrain meant Dave was unable to get himself out of the water.

“But Jane was nearby, and after hearing the splash, she slid down to desperately try and pull Dave out.

“Due to the steepness and slipperiness of the bank, she was able to grab his arm, but soon began slipping into the river herself.

“Dave’s final, decisive act was to let go of Jane’s arm when he realised she was falling in, despite knowing she was his only lifeline. Within moments, he was taken.”

Carey writes that Hogbin’s brave decision in that terrifying moment very likely saved his wife’s life.

Although the children were nearby, they did not witness their dad’s final moments.

His wife Jane said the family had lost a wonderful husband, father, son, brother, friend and doctor.

“We were just enjoying a standard day of our holiday and everything just changed within 30 seconds. He wasn’t doing anything wrong – in fact, he was doing everything right, and this still happened. Things can change so quickly in an instant despite doing everything right.

“He saved me – his last act was to not pull me in with him. I’m glad I’m still here, because it could have been a millionfold worse for everyone involved, not just the boys.

“I have a lot of comfort in knowing there’s nothing that I’m frustrated or angry about – he was just walking around a corner on a well-worn path. There’s no regrets about it, because it’s one of those random accidents that happen and nothing could have been done to prevent it.”

Dr David Hogbin fell into the river and failed to resurface. Photo: Supplied

Queensland Police have confirmed human remains were found inside a crocodile at Cooktown after it was humanely killed on Monday.

Rangers had targeted the crocodile with a distinctive scar near its snout as an extensive search for Hogbin lasted three days.

Police said formal identification was under way. The reptile was located in a creek four kilometres upstream from the suspected attack.

Wildlife officers began surveying crocodiles in the area after revealing on Monday the “target animal” had a distinctive marking.

“There have been some suggestions that the crocodile may have a white scar on its snout,” the Department of Environment, Science and Innovation’s Daniel Guymer said.

Hours later, rangers confirmed a helicopter search had found the reptile in a creek four kilometres upstream from the suspected attack.

“Wildlife officers have humanely euthanised a large crocodile that is believed to be responsible for the fatal attack on the Annan River,” the department said.

“The animal had markings on its snout that were consistent with it being the target animal.

“Wildlife officers are removing the animal from the creek and will hand it over to the Queensland Police Service.”

Authorities on Monday expressed their sympathy to the missing man’s family and friends during a “very traumatic time”.

Police are rallying around the family, offering them “all available support for their wellbeing”.

Wildlife officers on Monday revealed they were investigating social media videos that have emerged of people feeding a crocodile at a location that appeared to be the Annan River.

Guymer said DESI was aware of the videos, describing it as “very, very concerning behaviour”.

“It is very risky and it is very reckless. It is actually an offence,” he said.

“If people are feeding this animal … it will encourage that animal to stay in that area and that will present a safety risk.”

Anyone with information could report to DESI anonymously, he said.

The penalty for deliberately feeding a crocodile is a $6452 fine.

Police were working with wildlife officers as investigations continued.

A report will be prepared for the coroner.

-with AAP