Police hope drivers can provide film that shows an accident with a van in which a cyclist was seriously hurt.
Police are calling for people who have dash cams to come forward to see if they hold footage the crash.
The incident happened on October 19 on Winchester Road, in Wickham, at the junction of Blind Lane.
The cyclist, in his 50s, was taken by air ambulance to Southampton General Hospital following the crash with a Sprinter van at around 7am.
Winchester Road was closed in both directions in the morning causing long delays in the area.
Police say they are keen to hear from anyone who saw any white Mercedes-type vehicles and a cyclist which were both travelling south along the road prior to the collision.
Anyone with information should call PC 2762 Rob Tompkins at Eastern Roads Policing Unit on 101 quoting Operation Arrows.