We can now confirm that a motorcyclist has died following the collision on the A32 at Warnford at just before 7pm, Saturday, June 29.
A black Vauxhall Zafira and a grey Audi A6 along with a large articulated white truck were involved in the crash.
The motorcyclist, a 22-year-old man from Waterlooville, was taken to Southampton General Hospital but died on Sunday.
The section of the A32 where the accident happened was shut in both directions while officers investigated what happened.
We are now appealing for anyone who saw what happened or saw any of the vehicles involved shortly before the crash to contact us. We'd also like to hear from anyone who has dashcam footage of the incident.
They are asked to call 101 quoting Operation Junebug.
The driver of the truck, a 49-year-old man from Horndean, has been arrested on suspicion of causing a serious injury by dangerous driving. He has been released from custody but remains under investigation.