Poland is upset with Benedict Cumberbatch – because The Imitation Game gave Alan Turing all the credit for breaking the Enigma code.

Turing, often hailed as the grandfather of modern computing, was convicted of ‘gross indecency’ in 1952 after having sex with a man, and was chemically castrated, barred from working for GCHQ, and eventually driven to suicide.

The mathematical genius previously worked at Bletchley Park to crack the German Enigma codes – which is widely believed to have meant an earlier end to World War II.

However, his Enigma legacy has been called into question – as Poland contends that the Polish General Staff’s Cipher Bureau in Warsaw cracked Enigma before Turing, and helped show him how to build devices to come up with his method.

Maciej Pisarski of the Polish Embassy in Washington told the Telegraph: “The story of Enigma was very important to us and the breaking of Enigma code was one of the most important contributions of Poland to the Allied victory during the Second World War.

“Out contribution to Enigma is something that we learned a lot about as children in Poland but we have a feeling that the knowledge is not so widespread. It was a crucial association which gave the allies the edge over the Germans.

“We were trapped on the wrong side of the Iron Curtain during the Cold War which meant we did not get the credit that we should have received and nobody wanted to admit that anyone in Eastern Europe had anything to do with Enigma.”

Poland has launched historical exhibition ‘Enigma – Decipher Victory’ to remedy the misconceptions about the issue – celebrating Jerzy Rozycki, Henryk Zygalski and Marian Rejewski.

Pisarski said: “We felt it was important to fill in the blanks. It is our moral obligation to right this wrong and put this picture in a more complete way.”

Dr Grazyna Zebrowska, the embassy’s science advisor, added: “I think the real story has been lost over time.

“The Polish involvement was well known during World War Two but during the communist time it was not so convenient to admit that there had been so much cooperation between Britain and Poland. It was a very special and very secret alliance.

The tech expert added: “The Imitation Game film is all about Turing and everyone in Britain and it is just meant to be a short space of time, but I think there was an audible sigh in Polish cinemas when our contribution was reduced to just one line.

“We’re hoping this exhibition will show the work of the Polish mathematicians.”