Man drowns swimming at Wattamolla lagoon in the Royal National Park

A 27-year-old man has drowned at a beach just south of Sydney after being pulled unconscious from the water on Christmas Day.

Emergency services were called to the Wattamolla lagoon within the Royal National Park near Sutherland about 6.45pm on Sunday.

Kids jumping off rocks into Wattamolla lagoon. Photo: Tamara Dean

Police have been told that nearby swimmers saw the man disappear under the water. They searched for him and pulled him back to shore.

The man is believed to have been swimming at the beach with his friends.

A number of bystanders performed CPR while others contacted emergency services. About a dozen people were at the lagoon. 

NSW Ambulance paramedics and doctors arrived and took over performing CPR.

However, despite the best efforts of bystander and emergency service personnel the man died at the scene.

Police are now investigating all the circumstances surrounding the man's death will prepare a brief for the Coroner.

Police are urging people to remain vigilant around waterways, beaches and swimming pools during the festive season following today's incident.