Hi
Sorry to hear of your leak.
It is most likely oil filter housing/oil delivery pipe related if the engine oil level has definitely dropped.
Has it been serviced recently? If so it could be a badly seated o ring in the oil filter assembly, or a crack in the plastic filter housing cap, perhaps due to over enthusiastic tightening? I think the recommended torque is only 25Nm which is not much.
If you need any photographs of the area behind the wing, drop me a pm with your email address and I'll send you some.
