Flash light always on

I have a nokia 625 and the LED flash light is always on even when the phone is powered off. As soon as the battery is connected there is voltage on the LED pins. I can't seem to see any other fault with the phone other than the LED constantly on. I assume it's a main board fault?? Any ideas on where the LED driver is located? Or what causes it? I know with some other phones if the LED casing is accidentally grounded it stays on.

Cheers