Sherlock star Sacha Dhawan in new drama on growing up in Wolverhampton

Dhawan, who has also appeared in the BBC's Line of Duty, will play critically-acclaimed author Sathnam Sanghera, whose memoir The Boy with the Topknot forms the basis of the show.

He said: "After reading Sathnam's memoir – The Boy with the Topknot – I was so excited to hear that BBC, Kudos and Parti Productions were adapting it.

"Not only is it a beautiful story, but it's also funny and immensely moving. I feel incredibly proud to be playing Sathnam and look forward to telling a story, which has already touched so many people."

Born to Punjabi parents in Wolverhampton, Sathnam's memoirs are described by the BBC as a 'humorous, touching and emotional story of a second-generation Indian growing up in Britain'.

He said Dhawan is 'perfect' for role and talked about the 'strange experience' of seeing his book being turned into a show. The Boy with the Topknot will be screened on BBC 2.

He said: "I have hung out with Sacha, which was a surreal experience, he spent a day with me. He is a great actor and a great guy. He seems perfect, although obviously he is not good looking enough.

"I went to see the production office the other day and I did not realise so many people would be working on it, it is very exciting.

"I am going to the read through and depending on how that goes I will pop on set from time to time. The main thing is that it is good TV. I know they will not go wrong as I have the read the script and it is brilliant. They have managed to condense my book into 90 minutes of television, which I would not have been able to do myself.

"It does not matter how much the show varies from the book because the book is still there.

"It is a really strange experience to have your book being turned into a TV show but mainly it is exciting.

"I think the full reality of it will hit me at the read through when I see all these famous actors reading the lines. They are such big name actors as well, the guy playing my dad, Anupam Kher, is really famous in India. It is the opposite of writing because it involves so many people, writing is just you." Sathnam's book is an account of his childhood and facing up to painful family secrets and truths in his twenties.

Piers Wenger, controller of BBC Drama, said: "This powerful BBC Two drama tells Sathnam Sanghera's personal story about growing up as a second-generation Indian in the West Midlands and explores first-hand his experience of mental illness within a family.

I'm so grateful to Sathnam for allowing us to tell his story. With Mick Ford's beautifully touching script and the cast and production team that have come together to make this drama, it promises to be an unmissable film."

Other actors and actresses in the show include Joanna Vanderham, who starred in 2015 film The Go-Between, who will play the role of Sathnam's girlfriend, Laura, and Anupam Kher and Deepti Naval, from Bend it like Beckham and Lion fame respectively, who star as Sathnam's parents.

The drama will be directed by Lynsey Miller.