Emergency services were called to the accident on the Hume Motorway about 6.30am, following reports a car had hit a kangaroo at high speed in the northbound lanes. 

A NSW Ambulance spokeswoman said four people were inside the vehicle at the time, including a 19-year-old man who suffered a head injury and multiple cuts. 

“Two people were trapped and it seems one person might have been ejected from the vehicle,” the spokeswoman told the Mercury.

The ages and genders of the other three occupants were currently unavailable, she said.

The four occupants were taken to Liverpool Hospital – all of them in a serious condition.

The motorway was closed northbound, to allow officers from the Crash Investigation Unit to assess the scene, but has since reopened.

The crash caused major traffic delays, with northbound motorists diverted via Tahmoor and Picton. 

Southbound traffic was queued about 11km as a result of motorists slowing down to look at the northbound accident scene, the NSW Transport Management Centre said.