A murder investigation has been launched after the man was found dead in Harlesden.
Police officers were called to Casselden Road, in Church End & Roundwood, at 11.45pm last night (August 10) to concerns for the welfare of a man at a residential property.
After forcing entry to the property, they found a 40-year-old man with head injuries, Scotland Yard said.
He was pronounced dead at the scene.
The death is being treated as suspicious and detectives from the Met's Specialist Crime Command have begun a murder investigation.
The man's next of kin have been informed and they will be supported by family liaison officers.
A post-mortem examination to establish how the man died will take place in the coming days.
"At this early stage of the investigation, there have been no arrests," a Met spokesperson added.
Det Chf Insp Kelly Allen, leading the investigation, said: "My thoughts are with the family of the man who has died and we will do everything we can to support them as our investigation progresses.
"Based on our initial enquiries, we believe this was an isolated incident and there does not appear to be any wider risk to the community in Harlesden.
"I recognise the impact an incident such as this can have on people living in the area. Local residents will see extra patrols over the coming days to help reassure you and respond to any concerns you may have."
The London Ambulance Service said they did not attend the incident.
Witnesses say cordons remain at the scene.
Anyone with information that could help the investigation should call 101 quoting CAD 8547/10Aug.
Alternatively contact Crimestoppers anonymously on 0800 555 111.
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