Painting reattributed to Gainsborough after six decades labelled unknown

Experts delighted portrait re-found but say this is cautionary tale', stressing importance of rigorous checks to avoid misattribution

After being consigned to dark storage rooms for up to six decades as the work of an unknown artist, a portrait of a one-armed naval veteran has been reattributed to the celebrated 18th century painter Thomas Gainsborough.

A fundraising drive has been launched to raise 60,000 for extensive conservation work on the painting and its frame before it is hung in the Queen's House, part of Royal Museums Greenwich (RMG), next year.