A man in his 50s has been found dead at home after allegedly being knocked to the ground during an assault by a man and a woman on Saturday night.
Thames Valley Police has launched a murder investigation after officers found the man on Brome Place in Barton, Oxford, at around 11.30am on Sunday.
The man was allegedly assaulted outside shops on Underhill Circus at around 9.30pm the previous night.
His friends had taken him home but raised concerns to police the next day after he did not answer the door.
Senior investigating officer Detective Inspector Mike Roddy, of Thames Valley Police's major crime unit, said no arrests have been made.
"We are in the very early stages of this investigation,” Mr Roddy said, “but it appears that the victim has sustained head and facial injuries, which were not reported to or treated by medical professionals.
"Although we have launched a murder investigation, we are currently keeping an open mind as to the circumstances that have led to the man's death.
“We would urge the local community not to speculate on the incident.
"However, at this early stage, we do believe the victim may have been assaulted by an unknown man and woman at around 9.30pm on Saturday evening outside Barton shops and was knocked to the floor.
"We are aware that he was taken home by friends, and the alarm was raised to us this morning after he did not answer the door to these friends who were concerned for his welfare.
"I am appealing to anybody who was in the area of Barton last night between 8.30pm and 10pm and believe that they witnessed the original incident to please get in touch with Thames Valley Police."
The man's family have been told and are being supported by specialist officers.
Anyone with information should call 101 quoting incident reference 858 of April 24, or call Crimestoppers on 0800 555 111.