Just before 6am, emergency services - including the rescue helicopter - were called to Picton Road, near Macarthur Drive, Wilton, following reports of a head-on crash.

Police have been told a vehicle towing a boat and a utility collided.

The male driver of the utility died at the scene.

His male passenger and the male driver and sole occupant of the second vehicle were both treated at the scene by paramedics before being taken to Liverpool Hospital.

They are both reported to be in a serious condition.

Two further vehicles were also hit and sustained minor damage. The drivers were uninjured; however, they have been taken to hospital for mandatory testing.

Officers from Camden Police Area Command established a crime scene and commenced initial inquiries into the circumstances surrounding the crash, which will be investigated by the Crash Investigation Unit.

Just before 8am, part of Picton Road remained closed, with eastbound heavy vehicles advised to use Hume Highway to avoid Broughton Pass.