"Secrets" is a 1973 BBC Television play by Michael Palin and Terry Jones of one-hour duration, starring Warren Mitchell as the owner of a chocolate factory.
It is only much later that quality control finds a chocolate containing a thumb to confirm the missing man's gruesome fate.
Faced with ever-increasing financial disaster, the factory decided to start a campaign designed to try to alter attitudes to what was effectively cannibalism.
This eventually proved a great success and the factory flourished to the extent that the chocolates had major advertising slots on TV, culminating in an advert which featured a "Game Show Prize" style of conveyor belt, where instead of prizes, the conveyor passed across the TV screen loaded with a selection of deceased bishops and judges and other notable persons, while viewers were reminded by voice and logo that "Only the Best People Go into Our Chocolates".
In 2004 this version was included as an extra on the Region 2 DVD of Palin and Jones's series Ripping Yarns.