A motorbike rider is fighting for life following a collision with a car on a major Melbourne freeway.

It’s understood a car and a motorbike collided on the Monash Fwy, near the Wellington Rd exit, at Wheelers Hill at 12.47pm on Saturday.

Police say the rider was travelling in tandem with another motorcycle at the time of the crash.

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The motorbike rider involved in the collision was taken to hospital with life-threatening injuries.

The second rider was not injured and has since been arrested by police.

He is expected to be interviewed in relation to the accident.

The driver of the car stopped at the scene.

“Major Collision Investigation Unit detectives are attending the scene,” Victoria Police said.

“The investigation remains ongoing.”

Only one lane is open in each direction on the Monash Fwy between Wellington and Springvale roads.

The transport department said the crash is causing “significant delays”.

Motorists should instead use Ferntree Gully Rd, Springvale Rd and Wellington Rd to re-enter the freeway, or exit earlier at Forster Rd or Blackburn Rd to reach Wellington Rd.

Drivers heading towards the city should consider leaving the freeway at Police Rd to use the Princes Hwy and Blackburn Rd.