Just when you think the mockumentary genre has been done to death along comes What We Do In The Shadows – a mockumentary about the undead. WWDITS is a fly-on-the-wall mock doc about a group of housemates in Wellington, New Zealand who, incidentally are vampires.

From this set-up the comedy almost writes itself. The joke is that while some of them are over a thousand years old they still haven’t learnt to do the washing up. This is a household that makes the Young Ones seems domesticated. The oldest member of the house, Petyr, is an 8000-year-old Nosferatu-type figure who lurks in the basement. I bet he has never even handled a mop in all that time.

The trick is to get the balance of comedy and horror right and WWDITS just about manages it. In between the gags there is plenty of gore as the vamps' idea of a good time is to bring their guests back to their pad and suck their blood.

The main attraction for comedy fans is Jemaine Clement of Flight of the Conchords. The film is written and directed by its co-stars Clement and Taika Waititi (Viago, pictured), though Clement, as 892-year-old Vladislav, actually looks more like Matt Berry thanks to a luxuriant moustache which has clearly taken centuries to grow.

There is another nice treat for Conchords fans in a cameo from Rhys Darby as the leader of a gang of werewolves who these Kiwi Draculas encounter on a night out. The face-off between the rivals has a nice hint of West Side Story/Grease to it. With added fangs and facial hair.

As vampire comedy films go I'm not sure if this is the best ever. The young Roman Polanski made a great one, Dance of the Vampires, which has just been turned into a stage musical in Paris. But it is great fun and ought to do well on DVD as well as in the cinema. And for lovers of Flight of the Conchords this is certainly something juicy to get your teeth into while you wait for the Conchords to fly again.

Released on DVD on April 13. Buy here.