Step forward Tom Basdon with an adaptation packed with references to recent events, alongside an abundance of timeless jokes. Farce may seem an odd way to expose a rotten constabulary but when, as the play mentions, all the inquiries, and inquiries into inquiries, and inquiries into inquiries into inquiries fail to change anything, the situation becomes so absurd that laughter seems the only response left to vent one’s anger and frustration.

And you can’t not laugh at Daniel Rigby, as his character who has been brought into the station accused of impersonating a psychiatrist wriggles out of that charge with much verbal dexterity, then takes the opportunity to impersonate a judge who’s investigating how a suspect fell out of a window during interrogation, and then a judge pretending to be a forensic investigator (with a wig and false arm, two of many props in his Liberty bag). He pretends to be on the side of the police while tricking them into revealing how corrupt they are. The hapless officers are led into ever more ridiculous explanations about what happened, as they try to cover their arses.

It’s not a long evening but it is packed with more jokes and visual gags than a whole comedy series. As absurdity piles upon absurdity with crazy logicality, Daniel Rigby rattles off his lines faster than a police car on a shout, while also throwing himself about the stage. The pace, as directed by Daniel Raggett, never stops, except for a moment when Mr Rigby gets off a table in comedic slow motion.

You would never pick Daniel Rigby out as a comic. He doesn’t have the face of say Rowan Atkinson or the gangly body of a John Cleese. In fact, the very ordinariness of his appearance in the lineup makes him funnier because what he says and does is all the more unexpected. He has a cheeky grin and his eyes glint with mischief- no wonder he was so successful at playing Eric Morecambe in the TV film Eric and Ernie. He talks in a slightly high voice that always seems to be verging on the hysterical, and his movements are sudden and surprising.

In fact, slapstick and physical comedy feature highly on the charge sheet: characters are punched and soaked in water, Mr Rigby throws files of statements into the air (they are after all just paper). And in a moment I loved, he starts writing on the whiteboard, runs out of space, and continues writing on the wall.

To compound the fun, The Maniac (so-called) says he is an actor, and, of course,  he is an actor. The conceit is used to create further anarchy. So he refers to and even speaks to the audience, which the other characters think it is in his mind. He deliberately breaks the fourth wall by throwing his jacket and later sweets into the audience, following the mention of pantomime.

The inventiveness feels as thrilling and dangerous, as hanging out of a window on the fourth floor.

The five other actors are all in effect straight men and a straight woman to Daniel Rigby’s clown. Tony Gardner as the Superintendent has the panicky face of someone who has been promoted beyond their ability, Tom Andrews is a Neanderthal bullying detective, Ro Kumar is a naïve young officer, Ruby Thomas plays a reporter more interested in her image than uncovering the truth. They all have good lines. Mark Hadfield, playing a confused inspector, says at one point: ‘Unconscious bias? I don’t what it is, but I hate it.’

Anna Reid’s set conjures up perfectly the plastic soullessness of a police interrogation room. I liked the way she placed the stage floor at an angle to the proscenium arch, as a further indication of the way the world is knocked out of kilter, not only by The Maniac but by the fact that the people who should uphold the law are breaking it.

There is a roll call of the names of real victims of Met police corruption near the end, and a statistic is projected onto the set after the curtain call stating that there have been 1862 deaths in British police custody since 1990. Accidental Death of an Anarchist is so shocking that it makes you wonder whether you should have been enjoying yourself quite so much. But this is the kind of defiant laughter that helps us through the worst of situations.

There’s so much madness and mayhem that it’s not surprising the play starts to run out of steam towards the end. Even so, you still feel you’ve had your money’s worth from this evening of non-stop eye-watering laughter.