Sir Rodger Hollis, KGB
The Retired Director-General of MI5 (The UK Security Service), was investigated several times as a Soviet spy. He was believed by the Fluency Committe and K7 to be the GRU/KGB mole 'Ellis'. Before joining MI5 Hollis moved in Communist and Soviet circles in China. Later he ran the MI5 counter-Soviet Intelligence department of MI5. Other enquires included the Drat Inquiry and Trent inquiry. The list of Soviet Intelligence infiltration of MI5, MI6, The Admiralty and GCHQ(Which works with NSA) in the Uk
involves many famous cases including the spies:

Dr Klaus Fuchs, Philby (MI6 Counter-Intellegence officer), Mitchell, Sir Anthony Blunt ( given imunity from prosicution and allowed to work in the Palace after being discovered!), Leo Long, Guy Burgess (a homosexual who defected), Maclean, Cairncross, Watson, Prime (a pedophile at GCHQ), Vessel (another pedophile), Mi5 officer Michael Bettany and Captain John King a cipher clerk in communications.

Rodger Hollis was believed to have been recruited by the Soviet GRU Intellegence offficer Sonia (who recieved 2 Orders of the Red Banner). MI5 did little more than thank the enquiry's for there time and began to cover up the inflitration. Mi5 fabricated and altered the defector Guezenko's statement to suit them selves. The cover up in respect of Rodger Hollis still continues at the MI5 web-site.
Click here to see the cover up in action
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Some Mi6 Intelligence operatives