In Grey Wolf: The Escape Of Adolf Hitler, Gerrard Williams and Simon Dunstan describe a ghastly pantomime played out in the names of the Fuhrer and the woman who had been his mistress.
According to the authors a Hitler double probably long-serving Gustav Weber and an unknown actress who was a dead ringer for Braun went through the charade of a civil wedding in the Fuhrerbunker after midnight on April 29.
But the following day the actress was poisoned and Weber shot in the head at close range by Hitler's trusted ally General Heinrich "Gestapo" Muller.
The stand-ins, claim the authors, entered the bunker after midnight on April 28 as Hitler, his beloved alsatian dog Blondi, and Braun, plus close confidantes and trusted SS guards, sneaked out of the blockhouse, into Hitler's private quarters and down a secret escape tunnel into the Berlin underground system.
Nazi puppetmaster Martin Bormann paused only to burn a note Braun had written to her parents saying she would not be able to contact them for a while.
Camouflaged in baggy SS uniforms and helmets, Hitler and his co-conspirators walked ankle-deep through water in the abandoned underground until they reached the Fehrbelliner Platz station. Three tanks were waiting to spirit them to a makeshift airstrip cleared on a wide road.
Williams and Dunstan say that from there the Fuhrer and his party were flown to Tonder in Denmark, then back to Travemunde in Germany, where they transferred to another aircraft.
It flew to a Spanish military base at Reus, south of Barcelona, where General Franco supplied a plane to take them to Fuerteventura in the Canary Islands.
There, Hitler and Braun boarded a U-boat, codenamed Grey Wolf, which took them to Fascist-controlled Argentina.
The couple settled in a remote Nazi enclave where they lived comfortably in a wooden chalet on money from looted gold and jewellery.
Journalist Williams and historian Dunstan spent five years travelling the world interviewing sources and undertaking research.
Their book completely contradicts the version of events written by respected historian Hugh Trevor-Roper, who interviewed bunker witnesses soon after the war ended at the beginning of September 1945. It flies, too, in the face of Russian authorities who claim to have the bullet-holed piece of Hitler's skull and a piece of his jaw held securely in Moscow.
Williams said yesterday: "I started looking at the story as a silly conspiracy theory but as Simon and I looked at more of the evidence it stopped being a silly story.
"Then two of our witnesses in Argentina got death threats and one said the Gestapo still operated in that part of the world."
He claimed that when they started looking deeper into rumours that have persisted since the end of the war that Hitler escaped to South America, they found plenty of testimonies.
South African-born former Luftwaffe pilot Captain Peter Baumgart had told a court in Warsaw in 1947 that he had flown Hitler out of Berlin.
The author claimed that Trevor-Roper had only interviewed two people to get the story of Hitler and Braun killing themselves and their bodies being burned and that both the witnesses had later admitted they lied to him.
Williams said: "They found the body of Joseph Goebbels but no body of Hitler. They were handed only dead doubles.
"They were handed six bodies, all of which were claimed to be Hitler, and none of them was. There is no forensic evidence for Hitler's or Eva Braun's deaths and the stories from the eyewitnesses to their continued survival in Argentina are compelling."
The authors claim independent scientists recently examined the fragments of the skull held by the Russians and found they were from a 40-year female.
They also say Hitler and senior Nazi politicians were allowed to make their escape to South America because Bormann had made a deal with the Americans to tell them where the Nazis' looted art treasures were.
And he had claimed that Germany still had weapons of mass destruction capable of hitting cities in America. US intelligence agents were happy to deal with the Nazi leadership in order to have control of German scientists and technology at the end of the war.
Details of the Nazi enclaves had been well-known in Argentina but it was only when the country became democratic after the Falklands War that people started to talk about it again.
Williams said: "We spoke to one girl who said she had served Hitler for three days at the house of a known Nazi sympathiser. The whole Nazi cabinet got to Argentina and no one went after them."
But for the story to be true, all those who survived in Hitler's bunker would have had to be in on the plot or taken in by the stand-in doubles. Rochus Misch, 94, Hitler's former radio operator and the last survivor of the bunker, wrote the book The Last Witness, telling conclusively how he saw the bodies of his boss and his wife.
The truth of the theory also depends on the entire crew of the U-boat which "took Hitler to Argentina" being executed, while pilot Baumgart was apparently trusted to live.
It also requires a conspiracy of American and Israel intelligence officers to have held strong for more than 60 years.
Historian Guy Walters said yesterday: "The theory that Hitler survived rubbishes decades of research by proper historians and intelligence officers."
