In 2020, Tate Britain hosted the launch of a new £20 banknote bearing representations of The Fighting Temeraire by JMW Turner and the artist’s most famous self-portrait. Now a leading expert has said the latter work, part of the Tate collection, is not by Turner at all.

Dr James Hamilton , who has published books on Turner and staged exhibitions at museums and galleries nationwide, said that while the painting does depict the English Romantic painter, it is likely to be the work of his contemporary, John Opie .

Hamilton told the Guardian he started researching the portrait because “there’s nothing else like it in Turner’s work”.…