Zalenby

Zalenby was an undercover policeman posing as champion racing pilot Horatio Hamilton.

He was investigating complaints from bereaved next of kin of former players of the Game of Death (in fact, none had survived).

He exposed the Nocturn activities and was supported by the law enforcing Judoon. (PROSE: The Game of Death)

Horatio Hamilton
As Horatio Hamilton he looked every inch the champion racing pilot. Dressed in a long leather flying coat, with silk scarf, he was handsome, had dark hair swept back and a devilish grin. Winner of the Mars–Centauri Grand Prix in fewer than 6 parsecs, he agreed to the Game of Death, apparently believing it to be the celebrity version where players were stunned, not killed. (PROSE: The Game of Death)