Enigma held to ransom

Bletchley Park Museum: daring daytime raid

A ransom letter demanding a "five figure sum" for the return of a machine which was vital in cracking Second World War German codes has been sent to the museum it was stolen from.

Detectives leading the hunt for the Enigma machine - stolen from Bletchley Park Museum - have revealed that a "highly unusual" letter was posted to chief executive Christine Large.

The typewriter-sized machine, believed to be worth more than £100,000, was taken from a display cabinet during an open day at the Buckinghamshire estate on 1 April.

During the war a team of mathematicians worked at Bletchley, which was known by the name Station X, to crack German codes.

Detectives believe the letter, typed on A4 paper, contained details of the machine that only the people who have it would know.

Broken English

A police source said: "The letter was in some kind of foreign language which had broken English in it."

On the day of the theft, detectives fingerprinted hundreds of visitors at the popular park in Milton Keynes.

The machine is one of only three in existence

Detectives had hoped the lengthy process of examining fingerprints might give clues as to who stole it.

During the investigation Thames Valley Police liaised closely with Interpol and specialist antiques squads all over the world.

The history of the Enigma machine is the subject of two Hollywood films - U-571 starring Harvey Keitel and Jon Bon Jovi and the forthcoming Enigma starring Kate Winslet.

The machine enabled the Germans to send encrypted messages which could only be decoded by an operator using another Enigma machine set up in the same way.

But very few were ever captured and the stolen machine is one of only three now in existence.

During the initial inquiry, police had suggested that the machine may have been stolen to order and that the thief may not realise its value.