In the tight-knit Ukrainian community of Cleveland, John Demjanjuk was known as a church-going family man.

He worked hard at the city’s Ford motor plant for more than 20 years and had three children. He was quiet, it was said, but friendly.

What his neighbours, colleagues and friends could never have guessed was that this shy bespectacled man may well have had the darkest of secrets.

During the Second World War, he was, it now seems likely, a Nazi concentration camp guard of such notorious sadism that he became known as Ivan The Terrible.

Among his most shocking actions were hacking the ears and noses off Jews as they were led to the gas chambers, a court eventually heard. He took particular glee in flogging women and children, it was told.

World War Two Photo Essay: The Final Weeks Show all 20 1 /20 World War Two Photo Essay: The Final Weeks World War Two Photo Essay: The Final Weeks World War Two Photo Essay: The Final Weeks April 28th 1945: Benito Mussolini and his mistress Clara Petacci are executed as they attempt to flee the country. Their beaten bodies are hung by their heels in Milan. World War Two Photo Essay: The Final Weeks April 30th 1945: Adolf Hitler and his wife Eva Braun commit suicide. World War Two Photo Essay: The Final Weeks April 30th 1945: Karl Dönitz succeeds as President while Joseph Goebbels succeeds as Chancellor. World War Two Photo Essay: The Final Weeks May 1st 1945: Joseph Goebbels and his wife commit suicide after killing their six children. Karl Dönitz appoints Count Lutz Graf Schwerin von Krosigk as Chancellor. World War Two Photo Essay: The Final Weeks May 2nd 1945: The Soviet Union announces the fall of Berlin. Meanwhile, the concentration camps Lübeck and Neuengamme are liberated by the British Army. World War Two Photo Essay: The Final Weeks May 7th 1945: General Alfred Jodl signs unconditional surrender terms at Reims in France, ending Germany's participation in the war. World War Two Photo Essay: The Final Weeks May 8th 1945: V-E Day commemorates the end of World War II in Europe, with the final surrender being to the Soviets in Berlin. World War Two Photo Essay: The Final Weeks May 9th 1945: Hermann Göring is captured. World War Two Photo Essay: The Final Weeks May 23rd 1945: Karl Dönitz and Count Lutz Graf Schwerin von Krosigk are arrested. World War Two Photo Essay: The Final Weeks Heinrich Himmler, former head of the Nazi SS, commits suicide in British custody. World War Two Photo Essay: The Final Weeks June 5th 1945: The Allied Control Council formally takes control of Germany. World War Two Photo Essay: The Final Weeks July 1st 1945: Germany is divided between Allied occupation forces. World War Two Photo Essay: The Final Weeks July 16th 1945: The first of an atomic bomb - the Trinity Test - takes place. World War Two Photo Essay: The Final Weeks July 26th 1945: Winston Churchill loses the 1945 general election. Clement Attlee becomes Prime Minister. World War Two Photo Essay: The Final Weeks July 30th 1945: The USS Indianapolis is sunk by torpedoes from a Japanese submarine in the Philippine Sea. World War Two Photo Essay: The Final Weeks August 9th 1945: A US B-29 Bomber named the Bockscar drops an atomic bomb - codenamed Fat Man - on Nagasaki. World War Two Photo Essay: The Final Weeks August 9th 1945: A US B-29 Bomber named the Bockscar drops an atomic bomb - codenamed Fat Man - on Nagasaki. World War Two Photo Essay: The Final Weeks August 15th 1945: Emperor Hirohito announces Japan's surrender on the radio. World War Two Photo Essay: The Final Weeks September 2nd 1945: World War II ends with the final official surrender of Japan being accepted.

Now, a new Netflix series exploring the still-baffling case of Demjanjuk has once again raised the question of just who this quiet Cleveland resident was and what exactly he did before his arrival in the US in 1952?

The series – called The Devil Next Door – is not the first time the question has been addressed.

As with the streaming service’s The Disappearance of Madeleine McCann documentary, much of what is included will be well known to those familiar with the story.

Yet the mystery of Demjanjuk – who was convicted of holocaust atrocities twice in two different countries but saw one conviction overturned and died with his appeal of the second pending – remains grimly fascinating.

What we do know about him for sure is that he was born in Ukraine in 1920, was drafted into the Soviet Red Army in 1940, and was captured by the Nazis in 1942. A decade later, he arrived in Cleveland, a married father and with enough mechanical know-how to get his job at Ford.

What we don’t know is what exactly happened in the years between his capture and the end of the war.

Demjanjuk maintained until his death in 2012 that he had been a prisoner at a labour camp before being forced to work as a guard and then fight for the Nazis.

Yet evidence suggests he actually volunteered to work at the notorious Treblinka and Sobibor extermination camps in Poland, where his horrific brutality, even amidst genocide, earned him his chilling “terrible” nickname.

It was in the late 1970s that the US government first announced its suspicions about this role in the Holocaust before revoking his citizenship and, in 1981, extraditing him to Israel for a drawn-out and high-profile trial.

There, several survivors of Treblinka identified him as Ivan the Terrible.

“I say it unhesitatingly, without the slightest shadow of a doubt,” said one, Eliyahu Rosenberg. “It is Ivan from Treblinka, from the gas chambers, the man I am looking at now… I saw his eyes, I saw those murderous eyes.”

He was found guilty and sentenced to death in 1988 – yet was sensationally acquitted in 1993 after new evidence came to light that it may have been a case of mistaken identity.

He was freed and returned to the US, yet questions about his wartime activity would not go away.

In 2002, an American judge ruled there was evidence that he had been a guard at Sobibor and, following complex legal hearings, he was extradited to Germany in 2009 to be tried as an accessory to the murders of 27,900 people.

It was a notoriously difficult hearing – with Demjanjuk’s actions difficult to pin down almost seven decades on.

Support free-thinking journalism and attend Independent events

No surviving witnesses could identify him as being at Sobibor during the Munich trial, meaning the prosecution relied almost entirely on documentary evidence – an SS identity card and recorded Nazi orders most prominent among them.

Yet it was enough to convict. He was found guilty of all charges and sentenced to five years in prison.