A former Waikato woman is feared dead after being taken by a crocodile in Australia.

Cindy Waldron, 46, who attended university in Hamilton, was swimming with friend Leeann​ Mitchell when the attack occurred.

Waldron was swimming at Thornton Beach, Daintree, North Queensland, about 10pm on Sunday when she screamed "A croc has got me."

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Mitchell, 47, who is also a New Zealander, tried but failed to drag Waldron away from the reptile.

READ MORE: Swimmer in Australia feared dead after crocodile attack

Cairns Police District duty officer John Rhodes confirmed a search is continuing for Waldron, who has been living in Australia for 18 years.

"She lives in New South Wales and was just up visiting friends," Rhodes said.

Mitchell, who grew up in Hamilton and went to Waikato University, is in the acute ward at Mossman Hospital, having suffered shock.

Mitchell's cousin Alan Frost, of Stratford, said she had just completed chemotherapy for cancer. He said friends are with her in hospital.

Rhodes said Waldron lives in the Blue Mountains town of Lithgow, which has a population of 21,000.

State emergency service crews are searching for Waldron on land, sea and from the air, Rhodes said.

Police have notified Waldron's family in Tauranga and Wellington. Family have declined to comment while the search is continuing.

"People go missing all the time," Rhodes said. "It's fairly rugged country, but this is the first time for a croc attack. Most people are aware of the dangers."

Douglas Shire Council communications officer Greg McLean was still learning of the details, but said as soon as a crocodile was known to be involved, the state rangers took over.

"I don't know exactly where it happened, but if it was on the beach, that is very unusual for a croc to attack on a beach. They live in estuaries and are usually in transit when on a beach, going from one estuary to another," McLean said.

It was about 10 years since the last fatal crocodile attack in the region.

"People tend to know where not to swim and not to swim at night [when crocs are feeding].

"It's really rare."

Lithgow Mayor Maree Statham said the community is concerned

"We feel very, very sad for her and her family. It's such a tragic accident," Statham said.

An Australia Zoo spokeswoman said it was sad this has happened because it perpetuates the bad reputation crocodiles have as bloodthirsty human hunters.

"Crocodiles are modern day dinosaurs. They are territorial, instinctual animals. If someone goes into their territory they will protect it, but they don't hunt people," she said.

To stay safe

· Always stand 3 to 4 metres back from the water's edge in croc territory (set up campsites, fishing etc. should always be that far back. Male saltwater crocodiles can strike from the tip of their nose to the base of their tail)

· Don't overhang the water. Crocodiles can use their powerful tails to launch themselves vertically to access prey - birds and bats - hanging in trees

· If using a boat in waterways in areas where crocodiles live, use appropriate, sturdy equipment.

· Don't swim in areas where crocodiles live. Crocodiles are built to survive in the water, it's their natural environment. Entering their territory is a risk that should always be avoided.

· Obey signage. Signs are placed in various areas across the North as a reminder and a warning to steer clear of crocodile environments.