A Cranbourne woman died following a collision in Ballan in early April and police will prepare a report for the coroner.
It is understood four motorbikes collided on the Western Freeway at about 1.50pm on 7 April.
Officers were told all four riders, who were riding in a convoy of seven motorbikes, came off their respective motorbikes.
Three riders were taken to hospital with non-life-threatening injuries.
The fourth rider, a 64-year-old Cranbourne woman, was airlifted to hospital with life-threatening injuries.
She succumbed to her injuries and died in hospital later.
The exact circumstances surrounding the crash are yet to be determined and investigations remain ongoing.
Anyone who witnessed the collision, with dashcam footage or information is urged to contact Crime Stoppers on 1800 333 000 or www.crimestoppersvic.com.au.
