Booker Prize-winning author Arundhati Roy is to publish her second novel - 20 years after her bestseller The God of Small Things came out.

The Ministry of Utmost Happiness will be published in June 2017.

"I am glad to report that the mad souls (even the wicked ones) in The Ministry of Utmost Happiness have found a way into the world," Roy said.

She has written a wide range of non-fiction but this will be her first work of long-form fiction since her debut.

"Only Arundhati could have written this novel," Roy's literary agent David Godwin said, describing it as "utterly original".

He added: "It has been 20 years in the making. And well worth the wait."

Simon Prosser and Meru Gokhale of publishers Hamish Hamilton and Penguin said in a statement: "To publish this book is both a pleasure and an honour.

"What an incredible book it is - on multiple levels; one of the finest we have read in recent times.

"The writing is extraordinary, and so too are the characters - brought to life with such generosity and empathy, in language of the utmost freshness, joyfully reminding us that words are alive too, that they can wake us up and lend us new ways of seeing, feeling, hearing, engaging.

"It makes the novel new - in the original meaning of novel."

The 54-year-old, who won the Booker Prize in 1997, is one of India's best-known authors.

She faced arrest for sedition for challenging India's right to rule over the disputed Kashmir region in 2010.

She is also known for criticising Western multinationals and the excesses of capitalism.

Roy recently featured on the cover of Elle magazine, saying she wanted to break the myth of the typical Indian beauty.

"I'm a black woman. Most of us are. Ninety percent of us are. This obsession that Indians have with white skin and straight hair makes me sick," she told the magazine.