A disturbing tale of male friendship which features graphic depictions of child sex abuse is favourite to win the annual Man Booker Prize for best novel, being awarded in London on Tuesday.

US author Hanya Yanagihara's "A Little Life" follows four young men after they graduate from college but focuses on the traumatic past of one of them, who was abused by monks as a child and self-harms.

The Guardian called the book, which is over 700 pages long, a "relentlessly harrowing human epic" while The New Yorker praised its "subversive brilliance".

Yanagihara, who also works as deputy editor of the New York Times Style Magazine, said she wanted to show a group of male friends in New York because "everyone is on the run in some way" there.

"I structured the book so there are five turning points where the mood gets darker," she told The Bookseller magazine in June. "Like taking a dial and giving it half a twist to the right."

It is 6/4 favourite to win the £50,000 (67,000 euro, $77,000) first prize, followed by Briton Sunjeev Sahota's "The Year of the Runaways" at 9/2 and Jamaican Marlon James's "A Brief History of Seven Killings" at 6/1.

They are followed by "The Fishermen" by Nigeria's Chigozie Obioma at 10/1, American author Anne Tyler's "A Spool of Blue Thread" at 12/1 and British writer Tom McCarthy's "Satin Island" at 20/1.

The relative lack of established big-name authors on the shortlist has raised some eyebrows though.

Salman Rushdie -- whose "Midnight's Children" took the prize in 1981 and was judged best novel ever to do so in 1993 -- said his days of winning were "gone".

"If you look at the list this year, other than Anne Tyler there seems to be a desire to move away from established names," Rushdie was quoted as saying in Monday's Daily Telegraph.

"No (Kazuo) Ishiguro, no (Margaret) Attwood, no (Jonathan) Franzen... I haven't been on a Booker Prize shortlist for 20 years, so those days are gone."

Authors who were on the long list but failed to be shortlisted included Marilynne Robinson and Anne Enright.

The Man Booker Prize was previously open only to authors from Britain, Ireland, the Commonwealth and Zimbabwe but this is the second year it has been open to all nationalities.