London: The authorised biography of Sir V.S. Naipaul that said his infidelity and mental cruelty may have contributed to his wife's death is tipped to win the richest prize in non-fiction writing.

Patrick French's "The World is What it is: The Authorized Biography of V.S. Naipaul" heads the shortlist for the 30,000 pounds Samuel Johnson prize, to be announced July 15.

Bookies William Hill have French's book at 5-2, followed by "The Suspicions of Mr Whicher: Or the Murder at Road Hill House" by Kate Summerscale (3-1); "The Whisperers" by Orlando Figes and "Blood River: A Journey to Africa's Broken Heart" by Tim Butcher (both 4-1); "Crow Country" by Mark Cocker (5-1); and "The Rest is Noise" by Alex Ross (6-1).

The book on Naipaul says the Nobel laureate had a 24-year affair with an Argentinian lover in the full knowledge of his wife Pat and visited prostitutes while she was alive.

A day after cremating Pat in 1996 he welcomed into his home a Pakistani journalist he had recently met - and they married two months later.

Journalist Rosie Boycott, who is chairing the judging panel, said: “All six books are ones which changed the way we looked at the world, they are all ones we are eager to pass on to others.”

Last year's prize was won by Rajiv Chandrasekaran for "Imperial Life in the Emerald City".