Civilian Scamera Operators

[Cooperman]

I may well be completely wrong here, but I thought that the Home Office Regulations or the ACPO Guidelines had stated that speed cameras and radar guns were to be used specifically "by police officers to check the speed of a vehicle which their own observation made them suspect was driving in excess of a speed limit", or something along those lines.
If this is the case, how can the scamera vans be operated by civilians?
Does anyone have the regulations to check this?