Police are investigating after vision emerged of a huge truck pushing a car along a stretch of busy highway in inner Sydney on Monday.

Paul Joyner witnessed it from his desk overlooking the Princes Highway at Sydenham.

“It started when I heard the tyre squeal,” he said.

He looked out his window to see the truck pushing the car along the road.

Mr Joyner said there was someone in the car at the time.

“There was about 20 or 30 seconds of tyre squeal,” he said.

“The truck stopped about 100 metres down the road, the truck driver hopped out but the car had dislodged.”

Mr Joyner said he suspected the truck driver wasn’t aware at first what had happened.

“In a big rig like that it would be hard to know,” he said.

A spokesman for the truck’s freight company said it was an accident.

“It was not fatigue, road rage, or ramming,” he said.

Police from the Traffic and Highway Command are now investigating after video of the incident emerged on social media.