Police will prepare a report for the coroner after a woman died following a collision in Ballan earlier this month.
It is understood four motorbikes collided on the Western Freeway about 1.50pm on April 7.
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 on Friday, April 19.
The exact circumstances surrounding the crash are yet to be determined and investigations remain ongoing.
Anyone with information can contact Crime Stoppers on 1800 333 000 or www.crimestoppersvic.com.au.
