Discovery 2 engine water leak?

Hi
My boss has a 2000 (W reg) discovery V8 auto and is loosing water. I have had a look for him and noticed water trickling down on the off side rear of the engine but cant pin point where it is actually coming from. Could it be a core plug or a leaking cylinder head gasket perhaps. Any ideas would be appreciated. Thanks.

typical problem with the td5 d2's is a core plug, although its not technically a core plug its more of a blanking plug which is under the exhuast manifold, take the heat shield off and get a mirror in there to have a look before taking the manifold off. I know you say yours is a V8 but its worth a look...

Thanks for the reply. I will give that a try.