The Hampshire & Isle of Wight Air Ambulance and the Dorset & Somerset Air Ambulance are both in attendance at the junction of Southford Lane and Newport Road.
Emergency crews rushed to the rural location at around 21:00.
It is unknown at this time how many casualties are involved.
Police have closed all roads in the area as they deal with the life-critical incident.
Firefighters from Ventnor have in the last few minutes arrived on scene.
UPDATE @ 22:10 – Police have confirmed that a motorcycle and a van have been involved in tonight’s incident, which is being treated as serious.
It is thought that at least 2 casualties have been involved.
In a statement, Police have said:
”Officers are currently dealing with a serious road traffic collision.
”We were alerted by the Ambulance Service to the incident at 8.47pm tonight (July 1), at the junction of Southford Lane and Newport Road.
“A van and a motorcycle are said to be involved in the collision and the emergency services are currently on scene.
“Road closures are in place on Southford Lane and Newport Road and the public are urged to avoid the area at this time.
“If anyone saw the collision or has any information or dash cam footage, please get in touch by calling 101 and quoting Operation Overlay”.
UPDATE @ 22:40 – The Dorset and Somerset Air Ambulance has taken off from Whitwell and has conveyed a critically ill patient direct to Southampton General Hospital.
Island Echo understands that the crash has involved a motorcyclist, a pillion passenger and a campervan.
Island Roads have implemented hard road closures in the area with Niton Road and Southford Lane expected to remain closed throughout the night.
The Collision Investigation Unit from the mainland is due on scene shortly.
UPDATE @ 23:37 – The Hampshire and Isle of Wight Air Ambulance has taken off from St Mary’s helipad and is en-route back to base at Andover.
Specialist investigators from the Collision Investigation Unit are now on scene and are conducting a forensic examination of the scene.
Further updates are expected on Thursday morning.
UPDATE THURSDAY @ 07:07 – Southford Lane and Niton Road have now re-opened to all through traffic following the conclusion of overnight investigations.
UPDATE THURSDAY @ 13:00 – A 62-year-old motorcyclist has been killed and a pillion passenger has been left fighting for their life following a crash on the outskirts of Niton and Whitwell last night (Wednesday).
Read more here.