At approximately 1.20am, police received a call from someone who had found a man lying injured in New Bedford Road, near to the junction with Telford Way.
Emergency services attended and the man was taken to hospital, where he remains in a serious condition.
Sergeant Simon Cooper, from the Bedfordshire, Cambridgeshire and Hertfordshire Roads Policing Unit, said: “We believe this man may have been a victim of a hit and run and a full investigation is underway.
"I’m appealing for anyone who was in the area at the time who may have witnessed this incident, or who has any dash cam footage of the nearby roads in the early hours of the morning, to contact us.
“We’re currently still working to identify the victim and inform their next of kin. If you have a son, brother, partner or male friend who has not returned home and you’re concerned, please get in touch.”
Anyone with information is asked to contact police on 101 or via www.beds.police.uk quoting Operation Islands.