K Branch MI5

Counter-espionage 1968-94

K Branch was a former division of the Security Service, MI5, responsible for counter-espionage in the service's organisation from 1968. Prior to this time, this had been D Branch (ref 1, p.860). The re-organisation was carried out by Michael Hanley as head of counter-espionage. Peter Wright claimed that he persuaded Hanley and Martin Furnival Jones to include a formal mechanism for investigating penetration of the service (ref 2, p.334). K branch was reincorporated into a new D Branch in the service's organisation of 1994 (ref 1, p.864).