knocking noise - 04 hse

Hi Guys,
The landy has developed a knocking noise recently which is very hard to trace.Its happening on general driving and almost all the time but cannot decide where it is coming from. Had mot a month ago and flew through,nothing was noticed as on its way or anything.Done usual check underneath for anything loose etc but dont really know what to check for so any advice would be great.
As stated does it regular and at all speeds/conditions, ie not just on rough roads etc.
It is the 1.8 hse, did have the HG done at 36k ish (warranty covered it)and never had any problems since until this strange dull knockin sound.
Any pointers appreciated.
Thanks Ian

Could be your diff mounts or rear subframe coming loose.

We had similar on one of our TD4s, tightening all front subframe mounting bolts sorted the problem.

try the drop links

Cheers for the replies, appreciate the suggestions. Gives me somewhere to start at least, its so annoying that the noise seems to "move about" and is not something you can pin to a certain spot as such.

Thanks Ian.