Liverpool museum appeals for information on subject of The Black Boy

Sitter for William Lindsay Windus's painting is rumoured to have stowed away on ship, possibly to escape slavery in US

The subject of the painting gazes at the viewer, alone and barefoot in loose and torn clothing. Known only as The Black Boy, his identity has been a mystery for nearly 200 years.

A museum is appealing for information about the mysterious sitter, who is rumoured to have stowed away on a ship to Liverpool - possibly to escape slavery in America - after research about the artist, William Lindsay Windus, and X-rays of the painting revealed potential clues to the boy's identity.