A 53 year-old cyclist suffered serious injuries after coming off his bike in Wimblington Road, Doddington.
at about 2.30pm on (Sunday).
The man cannot recall what happened and police are trying to trace witnesses in the hope of getting to the bottom of the incident.
PC Mat Smart said: “I am looking for witnesses as the victim cannot remember what happened so I do not know if it was a collision or if he had fallen off.
“He suffered quite serious injuries and I would urge anyone with any information to call police.”
Call 101 or Crimestoppers, anonymously, on 0800 555 111.