Italian author Andrea Camilleri, creator of the best-selling Commissario Montalbano series about a small-town Sicilian police chief, has died at the age of 93.

RAI state TV, which produced popular TV versions of his detective stories, interrupted its programming to announce his death.

Rome’s hospital system also announced the death, a few weeks after the long-ailing Camilleri had been admitted to hospital with heart problems and complications from a broken hip.

His books — most set in his native Sicily — sold 25 million copies in Italy, where literary bestsellers are usually measured by the tens of thousands.

He also had legions of readers overseas thanks to the enduring popularity of his character, police chief Salvo Montalbano.

Andrea Camilleri and Luca Zingaretti
Camilleri and actor Luca Zingaretti, who played his most famous creation on screen (AP)

Italian state TV versions of the series were so popular that even repeats consistently recorded the highest audience ratings. The shows were also exported to Latin America, Australia and across Europe.

The Italian actor who played Montalbano in every episode, Luca Zingaretti, wrote on Instagram: “Farewell maestro and friend.”

His position at the top of the book sales charts in Italy — Camilleri often had several books high in the rankings in the same week — was even more remarkable because the author sprinkled many of his works with words that many Italians are not familiar with.

He affectionately borrowed from the dialect of his Sicilian youth, which Camilleri saw as better lending itself to expressing characters’ emotions.

He had a brilliant ear for dialogue, drawing on his many years as a theatre and TV director and scriptwriter before his literary career took off when he was approaching old age.

TV adaptations of the Montalbano books used generous chunks of dialogue straight out of the printed pages, so smooth was the transition from book to screen.

“After 30 years in the theatre as a director, dialogue for me becomes fundamental in the structure of the novel,” Camilleri told the Associated Press in an interview in his Rome apartment in 2009.

The shows attracted millions of viewers with picture-postcard views of Baroque Sicilian towns, and tourists vied for turns to eat in the seaside trattoria where scenes of Montalbano dining out were filmed.

Between filming seasons, they traipsed through the beach town of Punta Secca to photograph the seaside house with inviting terrace where Montalbano lived, and took dips in the same waters where the character swam to clear his head when sleuthing got heavy.

Camilleri’s books travelled well, dialect and all.

“I don’t believe there has ever been another Italian author with so many books translated into English” in just a few years, Harvard University Romance languages professor Francesco Erspamer said.

Camilleri’s works were translated into 30 languages, including Chinese.

While the Montalbano police stories shot him to fame, Camilleri was versatile in his output. Among his works are a fictionalised biography of Nobel laureate Luigi Pirandello, who was born not far from Camilleri’s home town, and a dark novel about a sexually abused Sicilian boy’s childhood during fascism.

He produced his 100th book in 2016, when he was 90, dealing with the drama of thousands of migrants reaching Sicilian shores after rescue at sea.

By the time he wrote it, poor eyesight had forced him to dictate his novels to his assistant instead of creating them on his typewriter, where he used to work every day from before dawn for three hours.