As far as i am aware (which is fairly limited, as I normally stick to the Financial, Sports, and Page 3 (USA you lost out on this one
))...
Mr. Aziz was the Deputy for Mr. Hussain, although I suspect his role was purely diplomatic (not, saying he is innocent), compared to Saddam's sons and family who were not as effective diplomats (shooting someone is not a diplomatic solution in my book). However in his role as Deputy I do not think he was entirely separate from what Saddam was doing nor segregated from the general Human Rights abuses that occured under that regime.
I only feel that he should not be allowed Asylum rights in the UK (This would basically give him a free holiday under current British socialism rule) in return for his information. He may for his work (unproven) for the CIA and in the interest of National Security of the USA given the same chance any non-priviledged minority gets in the USA. ie. Work Hard, Get an education and prosper (at least thats what I believe in). Although earlier I liked the nice prison alternative as long as he pays for it. Beats being Dead in my book..
All this is IMHO only...