In the NHK's anime adaptation The Jewel Robbery at the Grand Metropolitan, John is the non-canonical name given to the valet in charge of the floor of rooms which includes that of Mrs Opalsen. Investigations by Poirot showed that he was actually a jewel thief wanted by Scotland Yard and that his real name was "David Kianzu" and that he conspired with the chambermaid Vanessa to steal Mrs Opalsen's pearls and then frame the maid Celestine. Inspector Miller later found the stolen pearls in his room. The character was voiced by Hiroshi Kamiya. In the original story, the valet was not given a name.