Precious Ramotswe, Botswana’s first lady detective, is the proud owner of what has undoubtedly become Africa’s most famous bottom. As the heroine of The No 1 Ladies’ Detective Agency, the popular series of novels by Alexander McCall Smith, she squeezes her ample backside frequently on to the seat of her tiny white van and sets off to solve crime.

Not surprisingly, it regularly breaks down, leading her into the arms of J L B Matekoni, who owns the Speedy Motors garage — as the television version, to be screened on BBC One tomorrow, lovingly chronicles.

Now the happy couple, who marry finally in book five, will be able to listen to the delights of live opera while the vehicle is being repaired.

McCall Smith, whose books have been translated into 44 languages and have sold 15 million copies in English alone, is converting the old garage that served as the inspiration for the fictional Speedy Motors, on the outskirts of Gaborone, into the only opera house in Botswana.

The Edinburgh-based writer, who regularly visits the country, has often driven past the disused building, but went in to inspect it only last summer.

“He fell in love with it immediately and said, ‘Wouldn’t this be a great place for music. Let’s convert it into an opera house’,” said David Slater, who ran the only theatre in Gaborone for 20 years.

The two went into business. A leaking roof was repaired. A new floor was put in and at a gala opening in June the No 1 Ladies Opera House — complete with small white van parked outside — will open its doors to the public.

“It’s all set to go now. We have about 12 musicians and then local singers so it’ll give people the chance to sing in an opera and have a bit of stage experience. They are really, really itching to do it,” McCall Smith told The Times yesterday.

Speaking from his home in Edinburgh, he described the venture as “an absolutely mad idea but tremendous fun”. The converted garage, which will double as a restaurant during the day, will hold only about 60 people and tickets will cost about £6.

McCall Smith, 59, declined to say exactly how much money he had invested in the project but it is thought to be thousands of pounds. “It hasn’t cost an arm and a leg but it’s a reasonable chunk of money. It’s a little miniature endeavour, but what a nice one. We’ll probably do one or two operas a year, but for a week in each case,” he said.

In the days of apartheid in neighbouring South Africa, the garage was used by migrant workers who were smuggled across the border to work in the mines. “They were brought here and given a meal and the vehicles that took them south were serviced here,” Mr Slater explained.

McCall Smith said: “It had such character, with lots of grease, old car seats for customers to sit on in the office, and I liked the feel of it. We had a look at it and realised if it was tarted up a bit it would be ideal as a small opera house.”

Residents of Gaborone are delighted at the prospect of a new tourist attraction in a city that boasts little except the modern glass and chrome offices of De Beers, the diamond conglomerate. “I think this could really take off,” Lindy Parry, who has leased the building to the writer, said.

“There is not much in Gaborone, but more and more tourists are asking about the No 1 Ladies Detective Agency and we’ll be able to bring them here, to No 1 Ladies Opera House, for a cup of coffee and sandwich,” Mr Slater said.

He planned to have a reading room with signed copies of McCall Smith’s books and others on the history of the country, he said.

The opera house is in the shadow of the magnificent Kgale Hill, which overflows with rare birdlife and is surrounded by a garden of leopard and leadwood trees and bursting with bougainvillea.

The television version of the No 1 Ladies’ Detective Agency, starring Jill Scott, the Grammy award-winning singer, as Precious Ramotswe, will be shown on BBC One at 9pm tomorrow. It was directed by Anthony Minghella, who died this week.

Botswana love affair

— Alexander McCall Smith was born in 1948 in Rhodesia, now Zimbabwe, where his father, a Scotsman, worked as a public prosecutor. He moved to Scotland as a student to study law

— Returned to southern Africa to teach law at the University of Botswana, where he helped to set up the law faculty and wrote a book on the criminal law system. Has always loved Botswana and visits every year

— Lives in Edinburgh with his wife, Elizabeth, a doctor, and two daughters. Is Emeritus Professor of Medical Law at the University of Edinburgh and remains an international authority on genetics, and an adviser to Unesco and the British Government on biotethics

Explore Books

• Book Extracts

• Book Reviews

• Books Group

• Audio Books

Times Recommends

• Superfreakonomics by Steven D Levitt and Stephen J Dubner
• The Times picks the 50 best paperbacks of 2009
• Vincent van Gogh’s letters show the soul of the artist