Saw this on the UK Talking Pictures channel, who are showing all 4 series of Maigret, originally early 60s BBC. We're in the 4th series now, and the quality has generally improved, this one no exception.
This story was also done in the Gambon series, and told in a very similar way too, though they had a longer time than the bare hour here.
Maigret gradually pieces together a tale that started a few years ago, in Cannes, with a trio of dancers and a boyfriend, who's now at the Hotel Majestic in Paris, where the murder occurred. His bank makes it look like he's a blackmailer, but is it really him?!
Diana Coupland plays a stripper, some time before she did Bless This House sitcom with Sid James, no problem to a skilled actress. And the American millionaire husband of the murder victim (she had been one of the French dancers) gave his voice to Jeff in the Thunderbirds!
AND - added in Spring 2023 - now we've seen the French version, Bruno Cremer as Maigret. It was told in a similar way (that series did sometimes alter the book story somewhat) but rather slower (nearly 2 hours runtime, so a lot of meaningful pauses).