Remains of a wartime carrier pigeon, above, were found in a chimney in Surrey, England. Intelligence experts have found the coded message it was delivering a challenge because of missing information. SWNS

LONDON—Britain's world-renowned code-cracking intelligence experts have admitted they've met their match—in a dead pigeon.

The U.K's secretive communications intelligence agency, known as GCHQ, issued a statement Friday acknowledging it has been stumped by an encrypted message found attached to a dead carrier pigeon believed to have been sent during World War II.

The skeleton of the pigeon in question was found in the chimney of a private home in Surrey, in southeast England. Tied to its leg was a small red canister with a handwritten message inside, under the heading "Pigeon Service."

The owner of the home, David Martin, began searching for someone to help him figure out the code—an effort that led him last month to the curator of the pigeon exhibit at Bletchley Park, a country estate some 80 miles to the north that had been home to the U.K.'s decryption experts during World War II and that today is a code museum.

Curator Colin Hill took up the cause and passed on the coded message to the intelligence agency. Their mission: to crack 27 five-letter codes, listed in four columns.

The expert code breakers at Government Communications Headquarters, or GCHQ, based in Cheltenham, believe the message is consistent with techniques used during the war, when senders often used codebooks that gave the translation of each group of four- or five-letter codes relevant for a specific mission. As an additional layer of security, the code groups themselves were sometimes encrypted by using methods such as a one-time key that both the sender and receiver could access.

Bletchley Park

But the current code-breakers quickly discovered they were missing key clues. The destination of the undated message is unknown, given only as "X02." And, although signed by what appears to be "Sjt W Stot"—an abbreviation of an old spelling of the rank of Serjeant—nothing is known of the individual.

Adding to the complexity: Although each pigeon used during the war was given an identity number, there were two such numbers in the message—NURP. 40. TW. 194 and NURP. 37. OK. 76—and either could have belonged to that particular bird.

"Unfortunately, much of the vital information that would indicate the context of the message is missing," said GCHQ in a statement.


The U.K.'s modern intelligence practice dates back to World War I when it sought to decrypt radio traffic sent between Germany and its allies. Over the years, it has intercepted an array of communications—from paper-based messages to ciphers such as those encrypted using the famous Enigma machine by Adolf Hitler's Germany, to messages sent via cyberspace.

Mr. Hill, a 68-year-old lifelong pigeon fancier and former builder, said GCHQ told him they weren't able to help because all the code books from the period had been destroyed. But he is skeptical about efforts made to crack it.

Given all of the modern-day computer equipment they have, "it's a little bit hard to believe," Mr. Hill said.

He remains determined to get to the bottom of it. Mr. Hill is continuing efforts to trace the pigeon's identity numbers and has enlisted the help of a woman in France—who used to be part of the Resistance movement during the war—to try to find the keys to the code.

He believes the pigeon was likely used by intelligence agents in Bletchley Park, in part because the message is in code rather than written in long hand, which is how many in the services sent messages.

During World War II, the U.K. government enlisted some 250,000 pigeons from owners across the country who signed up for the volunteer National Pigeon Service in exchange for pigeon feed.

The birds carried messages for the army, navy, air force and intelligence agents, including from behind enemy lines in Germany, France and elsewhere. Among vital intelligence they carried: messages about the location of German bomb-making factories.

Thousands of pigeons were killed in service, according to Mr. Hill. Some were killed when the planes they were being transported in were shot down; others were taken out by German marksmen as they flew over the French coast; while yet others were eaten by falcons once they returned to British territory.

Of the some 40 animals awarded the Dickin Medal during the war—the animal equivalent of the Victoria Cross awarded to humans for bravery in battle—about 30 were awarded to pigeons, said Mr. Hill.

Mr. Hill's exhibit currently includes hundreds of pigeon-related items, from Dickin Medals to the orange boxes used to carry pigeons on bomber jets, in case the pilot was shot down and needed to send a call for help. But he has his eye on the skeleton of the pigeon in question and its mysterious cargo.

"I'm hoping he'll donate it," said Mr. Hill of Mr. Martin, who found the bird.

Write to Cassell Bryan-Low at