A couple have died after a swimming tragedy at South Ballina last night.

About 7pm, the family of five from Sydney who were holidaying at a local caravan park went to the beach at South Ballina for a swim.

Police have been told the mother, a 44-year-old woman, got into difficulties in the water while swimming and her 42-year-old husband entered the water in an attempt to rescue her.

It is believed the couple got into difficulties in a strong rip and were unable to make it to shore.

One of their daughters rang Triple Zero on her mobile phone while her brother ran to the caravan park to get help.

Residents of the caravan park assisted in removing the man from the water and despite attempts to resuscitate him, he died at the scene.

Emergency services attended the beach, with the Lifesaver Rescue Helicopter and Ballina Jet Boat Surf Rescue Squad locating the woman in the water.

The woman was pulled from the water and transferred to the beach where attempts by paramedics to revive her were unsuccessful.

The three children, two girls aged 17 and 14 and a nine-year-old boy, were taken to Ballina Hospital where they were treated for shock and are now in the care of relatives.

Police investigations into the circumstances surrounding the drownings continue and a report is being prepared for the information of the Coroner.