On Tuesday 24 December at 5.30pm. Officers on patrol on Sandy Lane, Feltham were flagged down by a member of the public concerned about a man collapsed in the street.
The man, aged 33, had suffered a head injury and was conveyed to a London hospital by Ambulance.
Officers established a crime scene on the road side and at an address on Sandy Lane, both have since been closed.
The man subsequently died on 29 December, his next of kin are aware.
At this stage his death is being treated as unexplained and officers await the results of a post-mortem examination.
We are appealing for anyone with information in relation to this incident who may have seen the man prior to police attendance, or witnessed anything suspicious in the area, to call 101 quoting reference 4989/24DEC19.
If you have information but do not want to speak to police, please contact the independent charity Crimestoppers on 0800 555 111.