Vauxhall signum 1.9 cdti 120 fuel leak

[Gary1980]

Hi all I have a Vauxhall signum 1.9 cdti 120 8v 57 plate great cars well looked after where do I start 

diesel leak from back of engine I’ve had 3 starter motors with the same problem in mornings only to find that there is diesel leaking into it causing my problem the trouble is where would it be coming from 

I was thinking from union on the rail at the back of the engine as it looks like it is really wet 

anyone else had this problem 

and any suggestions would be great thanks all