According to the February 1970 edition of "Movie News" magazine (Australia), "Each separate location in Malaya was heavily guarded by the local police. They were particularly concerned about the rifles used in the film which were carefully checked in and out each night at the local jail. An official explained: "There are still outbreaks on the Northern borders and we take every precaution against it spreading". In fact, producers Leslie Gilliat and Ned Sherrin had to personally vouch for the gunpowder required for one scene".
When extras playing soldiers in the film trudged into Pinewood Lake on the studio's lot, they bumped into submerged cans of priceless British films from the 30s. The nitrate copies of these films was considered too unstable to be stored in crowded London during the Blitz, so they were stored in the more rural Pinewood Studios. The decomposing, dangerously flammable film was ultimately consigned to the lake as those in charge could not imagine their future value in the home entertainment industry.
During the scene where Brigg and Lantry are talking at the bar a young David Bowie can be very briefly glimpsed being escorted away by the barman. Despite auditioning and getting into the film, Bowie can only be seen briefly in this shot in the finished film.