BX hydraulic leak

[Sicile]

Hi everyone, Is there anyone who can give some help before I, or a mechanic starts work? I have a BX 1.7 TZD Turbo Break and a lovely thing it is too but the other day I got the hydraulic warning light. Thinking it might be that I hadn't checked the level for some time, I carried on home, only to find it was leaking freely from the O/S/R. Naturally the car dropped so that I couldn't get a jack under it but despite the leak I could raise the suspension enough to fit the jack.
The oil was soaking the front of the swinging arm and the mounting crossmember but even with the wheel off I couldn't locate the actual leak. It was far too much for a broken return tube so I assume it is the feed but it is so hidden it is difficult to confirm. The leak appears to be at the front of the assembly but before taking the whole thing apart which I guess will be necessary, does anyone have any advice or suggestions?
I'm hoping it won't be too much of a nightmare and would much appreciate any help.
Many thanks in advance