Police officers were on patrol in the town when they saw the victim, a man in his fifties on the floor in Micklefield Road at the junction with Hicks Farm Rise at about 12.20am today.
The victim was surrounded by a group of males, who fled the scene when the police officers arrived.
As the police officers approached the victim, they ascertained that he was not breathing and therefore commenced CPR. A few minutes later, an ambulance crew attended and continued to give the victim CPR.
Sadly, despite the best efforts of the police officers and ambulance crew, the man was declared deceased at the scene. His next of kin has been informed.
The victim’s identity and his cause of death are yet to be confirmed.
Senior Investigating Officer, Detective Superintendent Ailsa Kent said: “Thames Valley Police has launched a murder investigation after the victim, a man in his fifties died in Micklefield Road at the junction with Hicks Farm Rise in the early hours of this morning.
“Our thoughts are with the victim’s family at this extremely difficult time. The family is being supported by Family Liaison Officers.
“When the police officers discovered the victim, he was surrounded by a group of males, who fled the scene when the officers approached in their police vehicle with its blue lights illuminated.
“We would urge any of the males who were at the scene to contact the police as soon as possible, as they may have vital information that can assist our investigation.
“We have arrested one man on suspicion of murder. He is in police custody at this time.
“I would appeal to anyone who was in the area of Micklefield Road and Hicks Farm Rise in the early hours of this morning, who saw or heard anything to come forward. If you have any footage, whether dash-cam, CCTV, mobile phone or doorbell camera, please retain this footage and contact the police.
“You can contact Thames Valley Police by calling 101 or visiting our website, quoting reference number 59 (31/7).
“Alternatively, you can contact Crimestoppers anonymously by calling 0800 555 111.
“There is a large cordon in place at the scene where the victim was found. As such, Micklefield Road, Hicks Farm Rise and a service road are currently closed. We apologise to residents for any inconvenience this may cause, but the area has been closed in order for us to carrying out vital examinations and enquiries.
“I appreciate that the news of this murder will shock the community, but please be reassured that Thames Valley Police is conducting a thorough investigation to establish what happened. Anyone with any concerns can speak to our officers at the scene.
“I thank the public for their understanding and support while we carry our investigation.”