INCA leisure battery draining

Does anybody have any idea why my leisure battery is draining quickly. 
It is a new battery and was charged fully but when the charger was turned off it went down to 9V in 5 days.
It was charged again and the fuse removed and has stayed at 13V all week.
I can see nothing turned on that would be draining it but I'm probably missing something obvious to more experienced owners.

There is a radio on/of rocker switch in the habitation area (where depends on the model of van) that, if left switched on (even with the radio off) drains the leisure battery in 4-5 days.

Didn't want to churp up before Peter, if you have a aerial boaster in the wardrobe ,check that its off.   
Boaby

Thanks for these answers. Have turned off the radio isolator switch and the aerial booster switch and the battery is still draining.
The battery is now being fully charged, apparently the charger in the motorhome does not charge it fully, and am waiting to hear from a motorhome mechanic to see if he has any ideas. 
This isn't too much of a problem on EHU but I do like to get away to CLs without electric every so often.

We are presuming that you are turning the 12v off on the Sargent control panel?

Peter, I've had a quick look in the manual and cannot see where to turn this off.  The control panel had no LED lights showing so I assumed everything was off.

It's the top left of the four on the panel and it does light up when switched on. There is a permanent supply to the fridge that bypasses the panel that powers the control board in the fridge so the fridge must be completely off.

Thanks. That was turned off.
Interesting about the fridge. I'll be collecting the recharged battery on Monday so will make sure the fridge is turned off when the battery is reconnected. I do only use the fridge on electric when on site but don't use it on 12v when travelling so didn't think leaving the dial turned to 240 would affect anything.

I have recently had this problem in my Devon. With the control panel switched on, in the status window it shows the battery being discharged two bars and with my meter on the bttery cable measures 0.3A approx. I took all the fuses out of the box under the seat and it still drains. The drain reduces to 0.1A with the control panel off. I also noticed that when switching off/on at the control panel I can hear a hefty clunk coming from the fuse box so I can only assume this relay/solenoid is the cause of the drain? I put this to the guys at the factory service centre today whilst other works were being carried out but appantly they could measure any drain so I am no further forward and will just have to remember to switch off the panel when we exit the van or go to sleep.