Tragedy struck when emergency services were called to help a yacht crew in distress.

A search operation has been suspended after a boating tragedy off northern NSW left three people dead.

Emergency services were called to waters off the Ballina breakwall about 6.15pm on Monday, after reports a yacht was experiencing difficulty off the South Ballina breakwall amid dangerous conditions.

A Marine Rescue vessel was launched to assist, but the rescue boat later flipped as it was crossing the channel through the mouth of the river, with a swell of up to five metres reported by locals.

A joint operation involving air rescue, SES, and NSW Ambulance was launched, with crews working in darkness and heavy spray.

Four crew members made it to shore and were treated by NSW Ambulance paramedics before being taken to hospital for further treatment.

Three others died in the incident.

NSW Minister for Emergency Services, Jihad Dib, confirmed two of those who died were Marine Rescue NSW volunteers, along with the mariner on board the yacht.

“It is with the heaviest of hearts that we mourn the loss of two brave Marine Rescue NSW crew members who have died in a tragic incident at Ballina,” he said.

“Our emergency services are the first to rush to the rescue of people in danger, and last night two of our courageous volunteers made the ultimate sacrifice.”

Police said the body of a man, believed to be aged in his 50s, was found on the sand near the scene. He is yet to be formally identified.

The body of a 78-year-old Marine Rescue crew member was recovered by the Westpac Lifesaver Helicopter, while a second crew member, aged 62, was located on the sand.

Four further crew members, aged 55, 75, and two aged 61, survived and were taken to hospital.

Authorities have now confirmed no one else was on board the yacht, which has since sunk.

Conditions at the river entrance off Ballina are widely regarded as hazardous, particularly in rough seas.