Diagnosis Murder has managed to attract something of a cult following in the UK, and it’s not difficult to understand how it has achieved this revered status. It’s camp, it’s gloriously predictable, it’s unintentionally hilarious and it has Van Dyke’s shoe-horned into every possible spare role.

DM stars Dick Van Dyke and his strong-jawed yet smoothly shaven son, Barry Van Dyke, as a father and son sleuthing team. Together, these two manage to stumble upon and solve a range of improbable crimes in the amount of time it would take most of us to finish a crossword. Dick is Dr Mark Sloane, an amiable senior doctor of something or other, who, despite having to run an entire hospital single handed, also finds time for a spot of crime solving. Barry is Steve Sloane, the quick-thinking cop with a maverick attitude that the ladies love, and the bad guys under-estimate. He always, ALWAYS comes out on top. And gets the girl. And sometimes, the last line, if his dad is busy tap-dancing.

That’s another fantastic aspect of the programme, it aims to showcase all of DVD’s considerable talents; tap dancing, roller-skating and comedy pratfalls. When’s the last time you tuned into a mild-mannered crime drama and were treated to a ball-room dancing display by the main protagonist? I very much doubt Inspector Morse could manage it.

But wait! Just when you were prepared to excuse Dick Van Dyke giving his son a rather generous helping hand on the old career ladder by agreeing to star in a TV series with him…..DM takes nepotism to the very, very edge. It seems that Barry isn’t the only family member with a burning talent and nowhere to take it.

Dick’s brother Jerry, his daughter Stacy and Barry’s four children, Carey, Shane, Wes and Taryn, have also all appeared in the show. Shane has appeared in 5 seasons, and Carey has played 6 different characters. An average episode often risks the viewers losing all interest in the plot, in favour of a game of ‘spot the Van Dykes’. They’re everywhere!

When Dr Sloan is out on the case, his quirky comrades, Dr Jesse Travis and Dr Amanda Bentley, must cope alone. They normally manage, and sometimes even uncover some handy evidence. Jesse strives for the kind of success that Steve Sloane enjoys with the ladies, but hasn’t realised that the dopey sidekick almost never finds love. Amanda is lovely, yet every so slightly moody and quite high-maintenance. Well, she IS a woman. These two, gawd love ‘em, can’t help but occasionally get mixed up in Dr Sloan’s remarkable escapades, but it always, ALWAYS turns out alright in the end. And then they have a jolly good laugh and perhaps a BBQ at Dr Sloan’s impressive beachside residence.

If you still need convincing, check out the frighteningly wide range of merchandise available on the internet. DM fever is raging like swine flu and you should probably request a house call.

Diagnosis Murder, BBC1, weekdays @ 2.15pm