A major search and rescue operation is underway after a Brisbane man went missing while swimming at a waterhole near Cairns that has claimed the lives of 20 people in the past 50 years.

Emergency services were notified about 8pm on Monday, two hours after the man disappeared at Babinda Boulders, south of Cairns.

The man was on a camping trip with a friend and the pair were swimming in a restricted area when the 37-year-old disappeared behind a large rock.

Acting Inspector Brett Jenkins said a large-scale search was underway.

“Every available resource that we have, has been put on to this. We will put everything into it that we can,” he said.

Police divers, SES, a rescue helicopter, ambulance officers and locals are all helping with the search.

Queensland Fire and Emergency Services Inspector Shane Jarvis said the area was extremely dangerous for swimming.

“You can be walking across the top of a rock system and the water will disappear underneath you,” he said.

“So there’s large caves and those caves are very, very deep.

“In places where they are able to see and get a visual, there are large logs that are very turbulent inside.”

Police said approximately 20 people had died at the pool in the past 50 years.

“It’s well known for being a dangerous area. I cannot stress the importance enough of not entering the water there,” Inspector Jenkins said.

He said police were assisting the man’s family.

“It’s obviously a very sad time for them, they’re obviously very concerned.”

The man’s friend, who did not wish to be identified, said he was trying to remain optimistic.

Tourist Norman Toward said he hoped the man would be found.

“The last time I was here was quite a few years ago and it was swirling and it looked very, very dangerous,” he said.

“I wouldn’t have gone in in a lifetime.”

-ABC