Help needed black humour TV movie

Hi, I'm French and I've got a few memories of a British TV movie I've seen in the early '80s. Since then, I've been unable to find the actual title.

It was basically the idea of "Kind Hearts and Coronets" in reverse. The story took place in the '20s or '30s. A young and naive heir to a lordship is supposed to be the victim of a curse: either he kills somebody or he'll die violently soon.

His bride convinces him the curse is true and tries to "help" him by setting up murders for him to execute. The bride actually tries to get him jailed so she'll get her hands on his money and will be free to be with her lover (also involved in the conspiracy). Unfortunately, the heir is very clumsy and fails miserably in all his attempts.

He makes a final try by sabotaging the car brakes of an old relative when everybody is in a country residence. The relative leaves the residence and is supposed to get killed in a car accident, as the road ahead is dangerous. The heir, who's actually an honest guy, writes a full confession of his murder. As soon as it is written, the bride takes it and leaves as fast as she can the house with her lover to bring the letter to the justice. Of course, she takes the wrong car, the one that was actually sabotaged.

A final voice-over informs us that the guy actually managed to be an assassin and was thus freed of the curse.

It could be a stand alone movie, it could be an episode in an anthology (similar to Ripping Yarns but longer). Anyway, I've got no idea of what it is...

It's ringing bells but nothing more I'm afraid.

Edit: No scrub that, it's reminding me of the Eric Idle/Catherine Zeta Jones film Splitting Heirs.

I had thought of this one but it definitely wasn't it.

There seems to be a whole tradition of movies of this kind. Actually, I've just discovered the movie was more than based on Oscar Wilde's "Lord Arthur Savile's Crime" but it took liberties with it. It might be a French TV adaptation from 1968 (which would explain why it can't ring a bell on this board and why I believed it was British, as it was still set in Britain).

It might help if you could remember what language it was in...

At the time, French television had only shows in French. I was 8 or 9 at the time I caught the movie, so I'm not able to tell you if it was the original language or a dub.

Sounds like one of the Comic Strip shows.

It sounds really good! If you can't find it, you should write it.