Overview

• Operation Wedlock was launched in the mid- to late-1990s after the CIA warned that a senior MI6 officer might be leaking secrets to Russia
• MI5 assigned up to 35 surveillance, planning and technical staff who covertly broke into the suspect’s home to install listening devices and live-feed cameras
• Surveillance teams shadowed the officer abroad using genuine passports under false identities, operating beyond the agency’s domestic legal remit
• The investigation continued in various forms until at least 2015, concluding inconclusively after the targeted officer departed MI6 without definitive proof of espionage
• Officials caution that the lack of conclusive evidence means a Russian agent could still be at large within MI6