A secret World War Two message found on a dead carrier pigeon has left 21st Century code-breakers baffled.
David Martin found the pigeon's skeleton in the chimney of his house near Redhill in Surrey.
A small, red canister attached to its leg proved it was a wartime carrier pigeon.
A piece of paper inside the canister had the code.
But experts from Britain's intelligence agency GCHQ admit it is impossible to crack without the original codebook.
Watch Simon Harris's report from 1st November 2012 - it features the code.