General Oil leak help!!

[Jimbo7x]

Hi everyone I have a oil leak on my 2001 2.8 D fiat ducato that's driving me mad I have recently fitted a new cylinder head but had the same leak before albeit not quite as bad, it looks like it runs down the right hand side below the rocker cover but doesn't seem to be the head gasket either it only runs down the side nothing on the front and only when it's running is there anything in between that could leak such as one of the tensioners bolts ????