http://www.bbc.co.uk/go/radio4/rhnav/choice/sat/t1/-/radio/aod/radio4_aod.shtml?radio4/litvinenkoI heard it - very interesting. The target of the dossier is not named (not surprising - they don't have proof that he ordered the murder, so they wouldn't be able to defend a libel case). It does name the 2 people said to have carried the polonium, and done the poisoning (I think they've been named elsewhere already - they claim they were contaminated when meeting Litvinenko about 2 weeks earlier, but that doesn't really fir with when his symptoms started); they think there was a 3rd person, not yet name, I think, involved.
The BBC have seen some of the dossier. The theory is that one of Litvinenko's associates was still an FSB informer, and Litvinenko showed him the dossier because they were going to work together on similar projects - checking out Russian businesses for Western companies thinking of working with them. The informer took it to the high-up Kremlin man, who then had he clout to get hold of the polonium. I think the idea was that it serves as a warning to anyoen who tries to investigate powerful people in the Russian government.