A 33-year-old motorcyclist who was involved in a collision with a car on the A5 near Towcester has suffered life-threatening injuries.
The crash, involving four motorcycles and two cars, took place near Towcester Racecourse shortly after 12.30pm, on Sunday.
A black Mitsubishi L200, being driven by a 50-year-old man, was on the A5 northbound, waiting to turn right into the racecourse, when a grey Yamaha R6, being ridden by a man, travelling southbound was involved in a collision with the vehicle.
At the same time a black Yamaha FZ6, being ridden by a 33-year-old man on the southbound carriageway was in collision with a silver Citroen C3, being driven by a woman northbound.
Two other riders, a 28-year-old man riding a yellow Yamaha R6 and a 43-year-old man riding a black Kawasaki ZX600, both came off their bikes as a result of the collisions.
Four further motorcyclists were travelling with the riders who came off their bikes, but were not involved in the collisions.
The 33-year-old man who was riding the black Yamaha FZ6 sustained life-threatening injuries and was taken to University Hospital Coventry by air ambulance.
The riders of the grey Yamaha R6 and yellow Yamaha R6 were also taken to hospital with minor injuries.
The A5 was closed near to the racecourse until around 5.30pm.
Police would like to speak to anyone who may have witnessed this collision or who may have any information regarding it.
Anyone who witnessed or who witnessed this incident is asked to call the Drivewatch Hotline on 0800 174615.