Woman hit by car while helping dying motorcyclist

The good Samaritan who was killed while trying to help a dying motorcyclist was a 27-year-old Melbourne mother of two.

She was hit by a car when she stopped at the scene of the road crash at Wantirna on Monday night just after 10pm.

The male motorcyclist, a 37-year-old Wantirna man, died at the scene after colliding with an Audi at an intersection.

Police say the woman who rushed onto the road to help him was a passing pedestrian, who is believed to have been struck and killed by a Honda Prelude.

Major collisions Acting Detective Inspector Brad McArthur described the incident as an "absolute tragedy".

"She's a mother of two young children," he told radio 3AW.

"Her partner is absolutely devastated and trying to take on board what's happened.

"He'll never get over this... The children now have no mother."

Police are investigating speed as a factor.

Acting Det Insp McArthur said a driver had stopped at an intersection, to see if any cars were coming from his right.

He saw a motorcyclist, though it was some distance away, and thought he could turn right, safely.

"But the motorcyclist came up on his right so fast.

"He was shocked by the speed that the motorcyclist was travelling.

"The motorcyclist hit his vehicle with such force, he's spun it 180 degrees."

Acting Det Insp McArthur said the woman was hit after she rushed onto the road to help the stricken motorcycle rider.

"In this line of work, we see the worst in people's behaviour on the roads. Then again, we see some really good people trying to do the right thing and ending up in circumstances where they're being killed or injured as well - this is a perfect example of that.

"We've got a person that was driving in an irresponsible and reckless manner, who's caused a chain of events that caused his death and the death of a person who was actually trying to help him out.

"It's a real contrast."

The 50-year-old Audi driver and his 47-year-old female passenger, both from Wantirna, were uninjured and stopped to help.

A 32-year-old Boronia man, who was the driver and sole occupant of the Honda, was also uninjured and stopped to help.

Police have spoken to all parties at the scene and the investigation is ongoing.