Police probe deadly crash after driver, 18, allegedly returns positive breath test

Police are investigating a deadly crash after the 18-year-old woman who was driving a ute when it rolled, killing a motorbike rider, allegedly returned a positive roadside breath test.

Police said the woman was taken to Stroud Police Station for a breath analysis in the aftermath of the horror multi-vehicle crash on The Bucketts Way near Booral just before 10.30am on Sunday.

Police confirmed on Monday that the teenager was "no longer in custody" while investigations continued into the circumstances of the collision.

Police were unable to comment further on the results of the woman's breath analysis while those investigations were under way.

Emergency services were called to The Bucketts Way near Gunns Gully Road, about 30 kilometres north-west of Nelson Bay, after reports a ute towing a horse float had collided with two motorcyclists.

A major multi-agency operation unfolded in response.

Port Stephens Hunter police officers rushed to the scene and found a ute pulling a horse float had flipped and rolled, crashing into the two motorcycles.

One of the riders, a man aged in his 30s, tragically died at the scene.

The Westpac Rescue Helicopter was deployed to fly the second rider, a man aged in his 70s, to John Hunter Hospital in Newcastle for treatment of serious leg injuries.

The older man was in a critical condition at that time. He remained in hospital in a serious condition on Monday afternoon, a Hunter New England Local Health District spokesperson confirmed.

Police said an 18-year-old woman was driving the ute at the time of the crash. NSW Ambulance paramedics assessed her at the scene but she did not require further treatment.

The woman allegedly returned a positive roadside breath test at the scene. It was then that she was taken to Stroud Police Station before she was later released.

Police confirmed the horse in the float at the time of the crash was uninjured.

Police set up a crime scene at the site, which was examined as officers worked to piece together the cause of the crash.

The Bucketts Way remained closed to all traffic for several hours while emergency services worked. Traffic was backed up in the area.