Car wont start, have replaced the battery, starter motor. I have checked cambelt timing. Ruled out petrol in the fuel as had the tank drained. AA have looked at it, Latest fault code to come up is P060600 Control Unit. It starts to crank over but doesn't start. does anyone have any suggestions? 

That looks like a generic OBD2 Powertrain code so you’ll most likely need to run a VAG specific tool to narrow it down to what is actually wrong.

Would recommend the above. Sounds like an ECU failure. Make sure all powers and grounds good to ECU first

 

Not sure if I've missed something, but is the car a Mk3? Is it still under warranty? If so, surely the best bet would be to get it to the dealer to sort it.