Illustration on page five of the manual MI5 still relies on highly trained “watchers”, these days rebranded as mobile surveillance officers, to follow suspects and gather intelligence.

“Watching” is a rudimentary but essential form of surveillance undertaken by the security service. Following targets on foot, public transport and sometimes into restaurants or ...

Use precise geolocation data. Actively scan device characteristics for identification. Store and/or access information on a ...

as part of a new exhibition on MI5’s wartime activities. Far from the glamour of screen spies, the booklet emphasises the demanding and often monotonous reality of surveillance work.

The guidance is contained in a booklet for recruits during World War Two, which will go on display at the National Archives in Kew, west London Rookie wartime MI5 "watchers" were advised they ...