Seized air con compressor

Hello All,
2003 Freelander ES Premium 2.0 TD4. I have a problem with the Aircon. I have smoke and noise coming from the compressor when it is on. When switched off there is no problem. It would appear that the compressor has seized and the smoke is coming from the pulley / clutch area and I don't know why. With everything switched off the compressor / pulley will not freewheel. Any ideas please! Meanwhile I have pulled the aircon fuse so I can have air on the screen.

Sounds to me like the Compressor is f$5ked ifthe problem is present when the aircon is switched on (Compressor clutch engaged) and dissapears when turned off (Disengaged).
Compressors are cheap enough from a breakers.
Take the car to an aircon place, get them to empty the gas out of the system, get a set of new "O" rings for the hose connections to the Compressor and a new drive belt. Remove the compressor.
Turn the new compressor upside down (Ports pointing down) and let the oil drain out overnight. Fit the compressor- DO NOT switch aircon on.
Mention to the aircon place that the Compressor has been drained of oil-they will then refill the system with the correct quantity of fresh oil whilst regassing.