People from around the world, from schoolchildren to war veterans, are trying to crack a World War II message found tied to the leg of a dead pigeon.

World War II experts suspect the bird was destined for the top secret Bletchley Park

The code, handwritten on a small sheet of paper headed Pigeon Service, was found in a small red canister attached to the bird’s skeleton up a chimney at a house in Bletchingley, Surrey.

Experts from the UK intelligence agency Government Communications Headquarters (GCHQ) have said the message, which has 27 five-letter code groups, is impossible to crack without its codebook.

They were also left stumped by missing details, such as the date of the message and the identities of the sender, ‘Sjt W Stot’, and the recipient, ‘X02’.

A spokesman said yesterday: “We have had about 50 people getting in touch since our request for help was published yesterday, mainly by e-mail but also some phone calls.

“They have been of varying ages, from school kids to people who were alive in the war. There have been men and women, and not just from the UK – from Holland and the US too. They’re approaching it from different angles, but no one has come through with a solution, saying this is what it definitely means, so the quest continues. It’s still early days.”

Historians believe the bird may have been dispatched from Nazi-occupied France on June 6, 1944, during the D-Day invasions.

Because of Churchill’s radio blackout, homing pigeons were taken on the mission and released by allied forces to inform military chiefs in England how it was going.

Unlike other carrier pigeon messages, though, the one found by David Martin as he ripped out a fireplace while renovating his home is written entirelyin code.

World War II experts suspect the bird was destined for the top secret Bletchley Park, which is just 130 kilometres from Martin’s home. During the war, codebreakers worked there round the clock in top secret – deciphering Nazi codes, including Enigma.

Military pigeons were dropped behind enemy lines from bombers, whereupon resistance fighters picked them up, before releasing them homeward bound with top secret messages.

It is thought the destination X02 may have been Bomber Command.

The enigmatic Bletchley Park

• Bletchley Park, an estate located in the town of Bletchley, in Buckinghamshire, England, was the site of the UK’s main decryption establishment, the Government Code and Cypher School (GC&CS) during World War II.

• The ciphers and codes of several Axis countries were decrypted here, most importantly, the ciphers generated by the German Enigma and Lorenz machines. It also housed Station X, a secret radio intercept station, for a short while.

• Station X, London Signals Intelligence Centre and Government Communications Headquarters (GCHQ) were all cover names that were used during the war, and the latter was adopted for the successor peacetime organisation that still bears this name.

• The high-level intelligence produced at Bletchley Park, codenamed Ultra, provided crucial assistance to the Allied war effort.

• Sir Harry Hinsley, a Bletchley veteran and the official historian of British Intelligence during World War II, said that Ultra shortened the war by two to four years and that the outcome of the war would have been uncertain without it.