A teenager has been charged after a ute towing a horse float flipped and rolled into two motorcyclists, killing both on the NSW Mid North Coast.

The crash occurred on The Bucketts Way near Gunns Gully Rd at Booral, about 30km northwest of Nelson Bay, about 10.20am on September 20. 

One of the riders, a 33-year-old man, died at the scene.

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The second rider, a 72-year-old man, suffered serious leg injuries and was airlifted to John Hunter Hospital in a critical condition. Police were notified on Saturday that he had died in hospital.

The 18-year-old driver of the ute was assessed at the scene but did not require further treatment.

She was taken to Stroud Police Station, where she allegedly returned a breath analysis reading of 0.053, before being taken to Dungog Hospital for mandatory testing.

The reading was just above the legal limit of 0.05 for fully licensed drivers in NSW. 

Two motorcyclists died after the crash. Credit: Booral Rural Fire Brigade

Following an investigation, the woman was charged with two counts each of dangerous driving occasioning death and negligent driving occasioning death.

She was also charged with negligent driving not occasioning death or grievous bodily harm, driving with a low-range prescribed concentration of alcohol and failing to comply with the conditions of her licence.

She was issued a Court Attendance Notice to appear before Raymond Terrace Local Court on November 23.