British Writers and MI5 Surveillance 1930-1960 by James Smith
[PDF file]: […] Koestler and Orwell? An MI5 officer assessed Koestler as ‘one third genius, one third blackguard and one third lunatic’, which seems pretty fair. His trajectory from Comintern agent to Cold Warrior is usefully documented, right up until the time that he became too hawkish for his new employers. Most controversial, of course, is George […]