"The Strange Case of the Missing Corpse" was filmed in colour on the set of "Honey for the Prince" and was, as Brian Clemens originally wrote it, intended to be tagged on to the end of the final b/w episode transmitted in America to advertise the upcoming colour episodes (though the b/w sequence titled "Preamble for USA", written by Clemens to introduce the item, which was to have featured Rigg and Macnee explaining/introducing this short colour test film, is either lost or was never filmed). It was also cut down into a trailer for the colour episodes coming soon to ABC Network in America. Just like the prologue to the b/w Rigg episodes, it was never meant to be screened anywhere but the US. There is a myth that it was to have originally been a twenty-minute mini-episode, but the version presently available on video is three minutes long and doesn't appear to be missing any substantial narrative content.