Author of bestselling memoir The Salt Path accused of lying

Gillian Anderson, who plays Raynor Winn in the film adaptation of The Salt Path, with Winn – whose real name is Sally Walker, according to the Observer. Photograph: Gisela Schober/Getty Images

It has been one of the films of the summer so far – the tale of Raynor Winn and her husband, Moth, who embark on the 630-mile South West Coast Path walk after their house is repossessed and Moth is diagnosed with a terminal illness.

There has been almost universal praise for the life-affirming story of The Salt Path, which has won rave reviews from critics. Until now.