Where is the petrol flap manual release for the Renault Meg Scenic (W Reg) ?

The central locking has gone on my Renault Megane Scenic (W Reg) therefore I am unable to open the petrol flap, can anyone tell me how to do this as I have looked in the boot behind the light where there is a picture of a petrol pump but I cannot see any levers or anything to release it.