Emergency services were called to Bolong Road just before 12.30pm on Thursday after a Toyota Camry and Holden Barina collided.

The driver of the Barina, a 79-year-old man, died at the scene.

His 72-year-old wife was airlifted to St George Hospital where she died early on Saturday.

The driver of the Camry, a 35-year-old man, suffered serious injuries and was taken to Wollongong Hospital for treatment.

He remains in hospital where he underwent mandatory drug and urine testing.

A two-year-old boy, who was a passenger in the Camry, remains in hospital in a serious condition.

Officers from the Southern Region Crash Investigation Unit are continuing their inquiries into the circumstances surrounding the crash.

A report will be prepared for the Coroner.