Swimmer dies off Shellharbour South Beach after large-scale search.

The man's body was found by his distraught family after it was washed ashore following a four and a half hour rescue operation.

Emergency services were called to the unpatrolled beach about 1.30pm to reports a swimmer had gone missing.

Two other male swimmers managed to return to shore.

A large-scale search commenced to find the man, which included an ambulance rescue helicopter and a Surf Life Saving chopper and Marine Rescue boats.

Council lifeguards and surf life saving crews also attended the scene and were on jet skis trying to find the man.

NSW Police officers coordinated the search from the beach while ambulance crews remained on stand-by.

At 5.15pm, the man's body washed ashore and members of his family pulled him onto the beach and started CPR.

Lifeguards, a Surf Life Saving duty officer and ambulance crews also tried to resuscitate the man but he could not be revived and he died at the scene. A police spokesperson confirmed reports will be prepared for the coroner.

Download the Illawarra Mercury news app in the Apple Store or Google Play.