Detectives have begun a murder investigation following the death of a man they believe was seriously assaulted earlier this month.
Officers believe the 27-year-old victim was attacked by up to four men in or around the Racecourse park in Northampton on 4 July.
The victim, who has not been named, collapsed a week later and was taken to Northampton General Hospital.
He was later transferred to University Hospital Coventry with a serious head injury but died on Sunday.
A post-mortem examination will take place in the coming days and his family are being supported by trained officers.
No arrests have been made and detectives are keen to hear from anyone who may have relevant information.
Detective chief inspector Adam Pendlebury of Northamptonshire Police, leading the investigation, said: “Having spoken with the man’s relatives, we believe he was assaulted by a group of up to four men while in the vicinity of the Racecourse at some point between 6am and 8pm on 4 July.
“We are working at pace to establish the timeline and circumstances of this assault, which appears to have left this man with injuries which tragically have proved fatal.
“I know there will be concern within the local community at what has happened, and I would urge anyone who is worried to speak to one of our officers – we currently have an increased patrol presence in the Racecourse area and are very keen to speak to anyone who may have information which will help our inquiries.
“Specially trained officers are supporting the man’s family at this desperately difficult time, and our thoughts are with them all in their grief.
“We are committed to securing justice for this young man, and I would urge anyone with information, however small or trivial you may feel it to be, to get in touch with us as a matter of urgency.”
Call police on 101 quoting incident number 23000427923 or independent charity Crimestoppers anonymously on 0800 555111.
Information, images and video footage can also be sent to the investigation team online.