Probably a spoof of private eye films, involving the theft of a paralysing gas...
Or whatever. So many people asked to have their names taken off this, there weren't many credits left. Originally written by Cleese/Chapman, John Sessions was left bearing the responsibility. Involves many greats of British tv comedy, including the respected Spike Milligan. Their best work lies elsewhere.
About as far from Ernst Lubitsch that it is possible to get while still breathing air.