Police are appealing for witnesses following a fatal road collision on the A3 last night.
Officers were called at 11.05pm to reports of a collision on the southbound carriageway of the A3 near Clanfield.
A white Vauxhall Corsa had left the carriageway and came to rest on its roof on the nearside verge.
The driver, a 22-year-old woman from Waterlooville, suffered serious injuries and was pronounced dead at the scene.
Investigations into the exact circumstances of the collision are ongoing and officers are appealing for witnesses to come forward.
The driver of a black Ford Focus, a 26-year-old man from Portsmouth, has been arrested on suspicion of causing death by careless driving and driving a motor vehicle when the proportion of a controlled drug is suspected to be over the prescribed limit. He is currently helping officers with their enquiries.
There is no evidence to suggest at this stage that the two vehicles were in collision with each other.
Anyone with information about this incident or having seen either of these vehicles earlier in the evening are asked to call the Serious Collision Investigation Unit on 101, quoting 44160349433, or Crimestoppers anonymously on 0800 555 111.