Police are investigating three hardcore porn films that were shot atop an eight-storey council car park in Sutton, south London, just yards from the offices of town hall staff.
One 11-minute video was shot in broad daylight and uploaded to an internet porn site last week.
It is understood there are other films in circulation on the internet which have also been shot at the car park opposite the council offices.
A 'furious' local resident contacted Conservative councillor Tony Shields, highlighting the video and the surroundings it was filmed in.
"I have seen it and it is about as explicit as it gets. It wasn't a kiss and a cuddle. If you were coming back to your car with your shopping it would be very shocking," Mr shields revealed to the Daily Mail.
"The informants showed me the video on their doorstep on a tablet while I was out canvassing. They have subsequently contacted me to tell me there are not one but three videos."
The film shows a taxi driving around the borough with a 'client' in the back seat, the taxi later parks up and the Sutton skyline is then clearly visible in some of the more explicit scenes.
It is illegal to film on council property without its permission.
Councillor Shields, who has demanded a council investigation into security at the car park, said: "It is tempting to liken this situation to a "Carry On" film maybe "Carry On up the car park" but in reality it is profoundly concerning to see that hardcore pornographers feel safe to make a very explicit film in broad daylight at a public car park."
He added: "I did not think Sutton was a favoured porn film location but it seems it is rather the porn capital and Gibson Road car park is the film set."