Officers were called at about 9.05am to a report of a disturbance in Axe Close.
Upon arrival, police found a man in the road, who was believed to have been involved in a road traffic collision.
Emergency services attended the scene, but the man – who is in his 60s – was pronounced dead shortly after.
He has not yet been formally identified, but his next of kin have been made aware and are being supported by specialist officers.
Det Insp Iain Macpherson, from the Bedfordshire, Cambridgeshire and Hertfordshire Major Crime Unit, said: “We are working to establish the circumstances around this incident in which a man has lost his life.
“Our thoughts are with the victim’s family at this tragic time, and we are asking that anyone who has any information to get in touch with us.”
Anyone with information can call 101 or report online quoting “Operation Just”.