Cath Fletcher reviews 'The Last Leonardo' by Ben Lewis (William Collins, 2019) On 13 April 2019, The Times splashed on the headline “Fresh doubt over world’s most expensive painting”. Accompanied by a picture of the Salvator Mundi, controversially attributed to Leonardo da Vinci in a National Gallery exhibition of 2011, the newspaper reported on claims in Ben Lewis’s book The Last Leonardo that the attribution was now in doubt.