Firefighters from St Mary’s and Eastleigh were called to a car fire on the M27 eastbound between junction 3 and 4, at 10.48 this morning.
Police were requested for traffic management to allow firefighters to tackle the blaze safely.
Firefighters used hose reels and a dry powder extinguisher to extinguish the blaze.
One casualty was treated by firefighters at the scene, before crews used environmental equipment to contain a small diesel leak.
The stop message came in at 11.30am.