Police in South Africa have managed to recover human remains after an officer was lowered from a helicopter into a crocodile-infested river in the search for a businessman swept away by floodwater last week.

The reptile suspected to have eaten the missing man had already been killed, but Captain Johan "Pottie" Potgieter said it was still a nerve-wracking experience.

"The sharp end of a crocodile is not the best place to approach it," he told the News24 website.

After Potgieter had used a rope to secure the animal, both were hoisted away from the Komati River in the north-east of the country.

DNA tests will now be carried out to confirm if the remains are those of the missing man.

His car had become stranded attempting to cross a low bridge in the flooded river last week. By the time the police got to the scene, it was empty, leading them to suspect he had been swept away by the water, Mpumalanga provincial police spokesperson Colonel Mavela Masondo told the national broadcaster, SABC.

The authorities used drones and helicopters in the search mission and noticed a small island where a number of crocodiles were basking in the sun, recounted Potgieter, commander of a police diving unit.

He said that, based on years of experience, they could tell that one of the animals had recently eaten.

"Besides having a massively full tummy, he didn't move around or try to slip into the river despite the noise of the drones and the chopper," he told News24.

The reptile was then killed before Potgieter embarked on what police described as the "highly dangerous and complex operation" to recover it.

The massive crocodile, measuring 4.5m (15ft) and weighing 500kg (1,100lb), was then flown to the nearby Kruger National Park, where human remains were discovered inside its intestines.

Potgieter said that, in addition to the body parts, six different types of shoes were found. He said this could indicate it had killed other people, but not necessarily: "A crocodile will eat or swallow anything."

South Africa's acting police chief, Lt-Gen Puleng Dimpane, praised Potgieter for his bravery.