A man from Havant has been arrested after a collision between a car and a motorbike on the A27.
The motorcyclist was left with serious injuries after the crash on Sunday at about 12.10pm.
The collision happened on the eastbound route near to Portsbridge.
A 51-year-old-man, who was riding the motorcycle, was airlifted to Southampton General Hospital after suffering life threatening injuries.
Police and the Highways Agency close part of the road while a full forensic investigation was carried out.
A Hampshire Constabulary spokesperson said a 32-year-old man from Havant had been arrested in connection with the incident.
He has since been released but is still under investigation.
Police are looking for anyone who witnessed the collision to call the Operation Packet investigation team at the Roads Policing Unit on 101.