Chilling dashcam footage has emerged of the Porsche at the centre of the horrific multi-car accident in Melbourne on Wednesday.

The luxury sports car was captured speeding down the same freeway just a month before it was involved in the crash that killed four police officers.

The 41-year-old driver, who is known to police, was pulled over after allegedly driving at about 140kph on the Eastern Freeway on Wednesday afternoon.

He underwent a drug test which allegedly returned a positive result.

The two officers who intercepted the Porsche called for backup when they decided to impound the vehicle, with two other members soon arriving.

Shortly after, a refrigerated truck ploughed into the police officers.

In the video below, the Porsche is seen speeding a month earlier

Play Video Porche involved in Melbourne Police crash tragedy filmed speeding a month earlier Porche involved in Melbourne Police crash tragedy filmed speeding a month earlier

Motorist James Tsagros said he saw the same Porsche “fly past” in a 100kmh section of Melbourne’s Eastern Freeway on March 21 and captured the moment on his dashcam.

“This guy flew past,’’ Tsagros told the Herald Sun. “It was just a flash.

“I have never in the 30-something years I have been driving experienced anyone drive past me doing that speed. It was actually scary.”

Tsagros reported the incident, which took place just 5km from the CBD, to police the next day.

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“I was expecting further down to see some type of collision,’’ Mr Tsagros said.

“He was just weaving in and out of cars.

“He just disappeared and he was nowhere to be seen.”

The Porsche driver fled the scene on foot after taking graphic photos of the crash and posting them on social media.

He is expected to present himself to police on Thursday, Victorian Chief Commissioner Graham Ashton told reporters.