Police have released a photo of a potential key witness to a serious collision on the A35 and are asking for the public's assistance to identify him.
The collision occurred at around 1.10pm on Saturday 7 May 2016 between three motorcycles on the westbound carriageway of the A35 between Yellowham Hill and Puddletown. It is believed the motorcycles were part of a group of seven.
Four people, all from the Southampton area, were injured.
Two of the injured – a 16-year-old girl and a 23-year-old man – were taken to Southampton General Hospital. They both remain in hospital with life-changing injuries, however, they are now not deemed to be life-threatening.
Two men aged 21 and 28 were taken to Dorset County Hospital for treatment to serious, but not life-threatening injuries and have since been discharged.
Both lanes of the A35 were closed for around nine hours while collision investigators examined the scene.
Police Sergeant Joe Pardey, of Dorset Police’s Traffic Unit, said: “Following a number of initial enquiries I am now able to release a photo of a man I would like to speak with in relation to the incident as I believe he may have witnessed the collision and can help me with my investigation.
"I believe this man was part of the group of riders, but those members of the group we have spoken to have unfortunately been unable to identify him.
"I would urge this man to contact police as soon as possible as he may hold valuable information regarding the incident.
"If you know who this man is, please contact me urgently on 101.
"I am also still keen to hear from anyone who either saw the collision or the manner of riding of any of the motorcycles involved as they travelled along the A31 and onto the A35."
Three men, aged 18, 27 and 28 and all from the Southampton area, and a 20-year-old man from Fareham have been arrested on suspicion of driving offences and are currently on police bail until the middle of June 2016 pending further enquiries.
Witnesses and anyone with information should call Dorset Police in confidence on 101 quoting incident number 7:199. Alternatively, call the free and anonymous Crimestoppers line on 0800 555 111.