Uretiti Beach Campsite manager Joe Foster said putting out crab pots was popular at the holiday spot, and people often walked into the water until it was up to their chins.
He said there was a big undertow at the beach at the moment, which might have swept the two men out.
Police said at least eight people had got into trouble in the water at Uretiti Beach in the previous 24 hours and most had been crabbing at the time.
They have urged beach goers to take care in the water.
"People are underestimating the conditions and overestimating their abilities, putting not only themselves but also those who go to their aid at risk," Sergeant Dan Cleaver of Northland police said.
"The easterly conditions that make the location popular for crabbing are the same conditions that make the beach dangerous."
He said police would not publicly identify the victim until family overseas had been notified.