Original sentence: According to the book published by Litvinenko's wife, ("Death of a Dissident") her husband's murder "gave credence to all his previous theories" and that the poisoning of Litvineko by Russian agents was "the most compelling proof" of all his theories:
Edited sentence: However assassination of Litvinenko, allegedly by Russian agents, was "the most compelling proof" of all his theories accoding to his biography book :.The involvement of the Russian government in the apartment bombings has been sometimes described in media as a "conspiracy theory"