A little-known gouache painting by René Magritte, the Belgian surrealist, has surfaced for the first time in more than 20 years and is expected to fetch up to €5 million at auction.

L’Incendie, or Fire, a 1947 work, pictures five overlapping trees in the form of giant leaves juxtaposed against a dark, foreboding sky.

Many experts see the painting, completed in the aftermath of the Second World War, as a metaphor for the destructive flames of conflict. The leaves are thought to signify joy and natural growth in a style the artist described as “sunlit surrealism”.

In a 1988 book on Magritte, Jacques Meuris, the Belgian photographer, wrote that trees and leaves in his work “may be regarded as ‘individuals’, invested with multifarious