Thanks everyone for the links and references - I will read and digest - it may take me a while!
Miles you are quite specific - TVM! However, after they have addressed the local causes, it would be good to hear just how deep investigators find themselves going before they find themselves constrained by time/money and possible reluctance/interference/brick walls?
Anyone out there care to comment or have recent relevant experience?
Any links to the Oz procedures and..
Anyone got a copy of Annex 13 itself?