Barrister-turned-broadcaster Rob Rinder thinks his friend Benedict Cumberbatch would be the ideal choice to star in a TV adaptation of his debut thriller The Trial.

He recalls how Cumberbatch, who he met at Manchester University, deterred him from pursuing a career in acting. “I’d been to the National Youth Theatre at 14 but, when I arrived at university, I did one play. I auditioned for it and thought the person who read after me [Cumberbatch] was so good.

“It was almost like hearing music in a different way, where I’m an amateur pianist and conduct a bit and then you watch someone really good do it and you think, ‘That’s what it’s supposed to be like.’ If I’d have networked really well I might have been able to get the odd bit part, perhaps in Eldorado.”

Cumberbatch officiated at Rinder’s marriage to now ex-husband Seth Cumming in 2013.

And Rinder was a best man at Cumberbatch’s wedding to theatre director Sophie Hunter in 2015.

The TV legal eagle made his name in reality court show Judge Rinder.

Now, he has channelled his legal experience at the Bar into his novel which begins with the poisoning of a policeman at the Old Bailey.

The main suspect, a career criminal, swears he didn’t do it so trainee barrister Adam Green must defend him. And, as he digs deeper, he finds a host of other suspects with motives to kill the inspector.

His own memories of his time as a barrister are also relived in The Trial.

“You very quickly normalise things that are not normal – be they spending a lot of time with violence or dead bodies, at the piercing edge of human behaviour and experience – and you gradually get surgeons’ or gallows humour,” says Rinder.

He’s still a member of his chambers. “I can’t do jury trials, but I try to answer questions every week, I still teach a little and I still mentor… My special interest is international law and the movement of criminal money.”

Rinder has appeared on TV shows from Room 101 to Strictly Come Dancing. Fame sits easily with him. “You call it fame, I call it privilege,” he says.

“People are really nice to me. You improve someone’s day just by smiling for a selfie. If you won’t do that, frankly you should get another job.”