UPDATE, TUESDAY 8.05am: Investigations into a crash involving two cyclists and a driver in Macedon are continuing.

A 44-year-old St Albans man was critically injured yesterday when he was hit by a car driven by a 26-year-old man from Parkville on Black Forest Road on Monday.

A second cyclist, aged 27 and also from St Albans, was also seriously injured in the same crash. 

No charges have been laid regarding the crash.

UPDATE, MONDAY 3.22pm: Detectives say a cyclist who was critically injured after being struck by a car in Macedon this morning is “in the fight of his life” at the Royal Melbourne Hospital.

Detective sergeant Mark Amos said the 40-year-old man was the most seriously injured of three cyclists involved in the collision on Black Forest Road shortly before 11am.

“As a result of the collision all three cyclists have been taken to the Royal Melbourne Hospital, one cyclist has suffered serious injuries, another, in comparison to his compatriots, has suffered relatively minor injuries, but importantly, one has suffered very critical injuries and he is in the fight of his life to try and survive,” he said.

Sergeant Amos said police were investigating whether distraction, speed or alcohol or drugs were factors in the crash and a 26-year-old Parkville man was assisting them with their inquires.

“On this long weekend, this is a very timely and sobering reminder of how seriously we need to take our responsibilities as road users and look out for each other, particularly when it comes to vulnerable road users like cyclists,” he said.

“Unfortunately, it’s a very good example of why we keep saying that distraction, speed, drugs and alcohol are killers and cause maiming injuries on our roads.”

UPDATE 12.45pm: Ambulance Victoria has confirmed paramedics treated three cyclists who were injured when they were hit by a car at Macedon this morning.

An Ambulance Victoria spokesperson said a man in his 40s suffered head and spinal injuries and his condition was stabilised at the scene before he was airlifted the Royal Melbourne Hospital in a critical condition.

The spokesperson said a man aged in his 20s also suffered head injuries and was taken by road to Royal Melbourne Hospital in a stable condition.

The third man was treated at the scene.

The driver of the car is assisting police with their inquiries and detectives are keen to speak with anyone who witnessed the incident.

UPDATE 12.30pm: Police have confirmed one male cyclist sustained life-threatening injuries in the crash, saying they believe a car “hit a group of cyclists” on Black Forest Road before 11am today. 

The major collision investigation unit is currently on scene with road closures and diversions expected to be in place for some time.

Police appealed for anyone who witnessed the collision or who has any information to contact Crime Stoppers on 1800 333 000 or submit a confidential crime report at www.crimestoppersvic.com.au 

EARLIER: Paramedics are treating two cyclists for head injuries after they were reportedly struck by a car in Macedon this morning.

Ambulance Victoria spokesman Paul Bentley said one of the cyclists was in a stable condition and being treated at the scene and the other transported to the Royal Melbourne Hospital in a critical condition.

Mr Bentley said paramedics were called to the scene at Black Forest Drive at about 10.45am.

More to come.