The strange case of a 94-year-old photograph some people said showed Britain's first black policeman may have been an accident, and he may have been white.
The original photograph of a crowd at a fire brigade demonstration in Chislehurst, Kent, in 1910 has puzzled historians, because it appears to show a black policeman more than 50 years before the first black man joined.
But, in a second image of the same scene, uncovered by Roy Hopper, of the Chislehurst Society, the man looks more Caucasian. Mr Hopper, a retired librarian, believes that the case of mistaken identity is down to a "photographic accident" caused by the slow shutter speeds and rudimentary equipment.
He said: ""I would be the first to cheer if it turned out to be a black policeman but I think it is one of those photographic accidents."
The first black policemen in Britain is believed to have been Astley Lloyd Blair, who joined the Gloucestershire force in 1964. In 1967, the Met had its first black recruit Norwell Roberts, who was awarded the Queen's Police Medal in 1996.
The Met's Black Police Association believes a mixed-race officer served in the Carlisle area in the 19th century. They were also contacted by relatives of two men said to have served in south London a century ago.