An off-duty NSW police officer has drowned in a rip after saving the life of a teenage boy at a beach on the NSW South Coast.

Surf Life Savers were called after a the 45-year-old became caught in a rip at Handkerchief Beach, south of Narooma, about 1.30pm on New Year’s Day.

When they arrived onlookers told them the man went into the ocean to rescue a 14-year-old boy, but after saving the teen he had disappeared under water, Surf Life Saving NSW Steven Pearce said.

A helicopter sent from Moruya spotted the man who was pulled from the rip by lifesavers, but they couldn’t revive him and he died at the scene.

“It’s a really, really tragic incident and we have numerous cases each year … where someone goes into the rescue and they, in turn, become the victim and the person they went to rescue successfully escapes the rip they were caught in,” Mr Pearce told AAP.

The man has since been identified as a serving NSW Police officer, who was off-duty at the time.

With warm temperatures driving thousands of people to the state’s beaches this summer, NSW lifesavers have already done more than 1000 rescues since Christmas, which is a record.

“We’ve never ever seen this before,” Mr Pearce said. 

“So the primary message today, particularly because it’s such a bumper day for the beach is: we’re urging people to go to a patrolled location, and that’s anywhere with a red and yellow flag flying and where our lifesavers, and our lifeguards, are on duty.”