A cyclist is in a critical condition after suffering head injuries in a crash in Lewes on Sunday May 25.
Sussex Police are appealing for witnesses following the incident which took place in South Street at 6.40pm.
It is thought the 49-year-old fell from his racing bike after colliding with a loose skateboard.
The cyclist was transferred from the scene to the Kent, Surrey and Sussex Air Ambulance.
The helicopter landed in a nearby supermarket car park and he was then flown to King’s College Hospital in London where he is being treated.
Sergeant Huw Watts said: “We would like to hear from anyone who saw what happened.
“They should phone Sussex Police on 101 or email firstname.lastname@example.org, quoting Operation Padstow.”