The emergency services are at the scene of an accident in Uxbridge, following reports of a person falling from a height.
The man reportedly fell from the Stanza building which is almost complete after months of construction and fitting out.
A London Ambulance Service spokesman said: "We were called at 12.43pm to reports of an incident just off Oxford Road. We sent a single responder in a car, an ambulance crew and a duty officer to the scene."
An air ambulance also attended, landing in Fassnidge Park.
Workers in the building were evacuated.
Police have cordoned off an area near The Crown and Treaty pub. The Swan and Bottle pub is also across the road.
Oil company Nexen Petroleum, which is currently based in Charter Place, also in Uxbridge, is due to move into the building soon.
A spokesman for Overbury construction said: “We are co-operating fully with the emergency services who are investigating an incident that occurred at our Nexen Petroleum site in Uxbridge.
"It would not be appropriate for us to comment further at this time.”
The identity of the man has not been confirmed. London Ambulance service estimate he was in his thirties or forties.
This is the fourth such incident of a fall from height from a building in Uxbridge in the last few months. Two men died in separate incidents, and one was injured after falling from the rear of The Grainges car park just across Oxford Road from the latest incident.
