The fatality occurred on Thursday morning at O’Rourke’s T2 multi-storey car park site where the worker was hit by a dumper truck.
The Enquirer understands that the victim was part of the night shift.
It is believed a mobile hoist broke down on the site and a colleague was using a dumper truck to try and move it when the truck came into collision with the victim.
A Met Police spokesperson said: “Police were called by London Ambulance Service at 04:46hrs on Thursday, 2 October to Cayley Road, close to the Ground Floor Car Park at Terminal 2, Heathrow Airport, following reports of a road traffic collision.
“Officers attended and found a man in his thirties suffering serious injuries following a collision with a truck.
“The man died at the scene a short while later at 05:45hrs.
“Next of kin have been informed but we await formal identification.
“A post-mortem examination will be held in due course.
“The driver of the truck stopped at the scene. It is not believed that any other vehicles were involved.
“The Health and Safety Executive has been informed and enquiries are under way into the circumstances surrounding the incident.
“No arrests have been made. Enquiries are ongoing.”
It is understood the £77m car park job is just weeks away from completion and hand over.
Laing O’Rourke has a “Mission Zero” policy aiming to eradicate all accidents from its sites by 2020.
The firm said: “Many people still believe that injuries – or even fatalities – are an unavoidable part of what we do. Laing O’Rourke does not accept this view.”