A cyclist who was involved in an accident in Hollybush Road on Sunday morning is being sought by police.
It is thought the cyclist was knocked from a bike by a black VW Golf at about 11am.
Beds Police officers were called to the scene and found a damaged bike on the ground but the car and cyclist had left the scene.
Four men in theire early 20s have been arrested in connection with the incident and a black VW car was recovered shortly afterwards.
PC Sam Shane said: “We know the cyclist was seen walking away from the scene towards the Lalleford Road area and I would appeal this person to come forward and speak with officers to ensure they receive any medical assistance they may need. I would also urge anyone who was in the area at the time of the collision to also contact officers and help piece together exactly what happened.”
The men arrested have since been released on police bail pending further investigations.
Anyone with information relating to this incident can contact PC Shane at Luton Police Station, in confidence, on 01582 394064, or Bedfordshire Police on 101, or text information to 07786 200011.
Alternatively contact the independent crime fighting charity Crimestoppers, anonymously, on 0800 555 111.