Lincoln In The Bardo was hailed as “utterly original” and praised by judges for its “witty, intelligent, and deeply moving narrative”.

The 58-year-old writer, who had been favourite to win, was presented with the prestigious literary award and STG50,000 ($A84,000) prize during a ceremony at the Guildhall in central London, attended by the Duchess of Cornwall.

Saunders becomes the second American author to take home the Man Booker Prize in its 49-year history, after Paul Beatty came top last year with satirical novel The Sellout.

The judging panel deliberated for five hours on Tuesday – including spells of “fierce debate” – before unanimously naming Saunders as the winner.

“The form and style of this utterly original novel reveals a witty, intelligent, and deeply moving narrative,” said Baroness Lola Young, chair of the judges.

Lincoln In The Bardo is the first full-length novel from acclaimed short story writer Saunders, who was born in Texas and lives in New York.

The book details the evening of February 22, 1862, when a grief-fuelled Lincoln visited his son’s crypt, exploring themes of death, grief and the possibilities of life, as well as the contrast between Lincoln’s personal tragedy and public role.

Saunders told Time magazine that he had not set out to write about the US statesman but was “captivated” after hearing about Lincoln’s visit.

“I thought of the book as a way of trying to instil the same reaction I’d had all those years ago,” he said.

First awarded in 1969, the Man Booker Prize is recognised as one of the most prestigious in the literary world, with previous winners including Salman Rushdie and Ian McEwan.

It is the fourth year the awards have been open to any writer regardless of nationality, provided the book was written originally in English and was published in the UK.

The 2017 shortlist also included 4321 by Paul Auster (US), History of Wolves by Emily Fridlund (US), Exit West by Mohsin Hamid (UK-Pakistan), Elmet by Fiona Mozley (UK) and Autumn by Ali Smith (UK).

-PA