The authoritative statements of the Thames Valley police (who, if I recall correctly from my time spent living in Oxford, seem to be a pretty nice and reasonably competent group of people) ought to outweigh the baseless speculation of people who hang around a notorious thug and gangster like Boris Beresovsky.

FORBES: There Still Isn't Any Evidence That Boris Berezovsky Was Murdered, But Luke Harding Wants You To Think There Is!

After Li's eldest son Victor was kidnapped by notorious gangster Cheung Chi-keung in 1996, the tycoon was said to have put in a word at top levels in Beijing. (Li himself brushed off the suggestion.) Mainland police caught Cheung, put him on trial and executed him.

CNN: Up, Up And Away