It's the bestselling book that's in the middle of its own seismic plot twist. Raynor Winn's The Salt Path spent 85 weeks in The Sunday Times Bestsellers List and has just become a film.

But the author's life-affirming account of how her husband's illness and losing their money and home put them on a 630-mile coastal walk has been called into question.

The Observer has claimed that not all of the couple's story stacks up - something strenuously denied by the author.Niall goes through the claims with Sky News arts and entertainment producer Jayson Mansaray and hears from a journalist who has interviewed Winn, Charlotte Lytton.

Producers: Emily Hulme and Soila Apparicio
Editor: Paul Stanworth