It's always Doncaster - a green G reg what looked like an Olympian.

It was a tri-axle decker, with windows that slid open sideways (not just a portion though, half of each window) and what can only be described as roll bars across the windows to stop people falling out.

Unless HM Prisons are transporting people around on double deck buses, I can only assume it is an ex Hong Kong vehicle.

Can anyone shed any light?

Edit: this is the bad boy I was on about! Www.flickr.com/photos/thespian/8167183947/

Edit edit: its not the same one, but very similar