A second person died following the Hampton Park collision that led to the death of a woman at the scene on 7 May.
A Toyota Hilux Ute and Toyota Corolla hatchback collided on Glasscocks Road at about 7.15am.
The driver of the hatchback, a 35-year-old woman from Narre Warren South, died at the scene.
Her passenger, a 34-year-old Narre Warren South woman, was taken to hospital with serious injuries.
The driver of the Ute, a 20-year-old Narre Warren South man was taken to hospital and died on 19 May.
Police will prepare a report for the coroner.
Anyone who witnessed the collision, with CCTV/dashcam footage or information is urged to contact Crime Stoppers on 1800 333 000 or www.crimestoppersvic.com.au.
