It sounds like a work of alternative history fiction: as Soviet forces closed in on Adolf Hitler's bunker in Berlin, the Führer fled in the nick of time to South America where he lived in hiding for another 17 years.

As far as conspiracy theories go, it's up there with Elvis and Roswell, but you'd better believe there are people who buy it.

It took nearly 75 years, but for the first time since the end of the Second World War, remains alleged to belong to Adolf Hitler were finally confirmed as authentic by a team of French pathologists in 2017.

Skull fragments and teeth held by Russian authorities in Moscow were presented to independent investigators for analysis, who concluded they were a match for the most famous dictator in modern history.

"The teeth are authentic – there is no possible doubt," lead pathologist Philippe Charlier explained to the AFP.

"Our study proves that Hitler died in 1945."

The teeth and bone fragments can now be traced back with confidence to a fateful day in late April when a defeated Hitler, hiding in a refurbished air raid shelter in the German capital, chose to take his own life by swallowing cyanide and shooting himself in the head.

hitlers teeth figure 1 ejim(P. Charlier et al./European Journal of Internal Medicine)

His body – together with that of his wife Eva Braun – was swiftly cremated in the bunker garden according to his wishes, even as Russian shells rained down in the near distance.

From there it's thought the charred body parts were gathered up by the Soviet forces who had stumbled onto the shelter several days later.

After a hasty autopsy the bodies were interred just outside of Berlin, only to be dug up and re-buried again in a forest near what is today known as Rathenow.

Another eight months passed before they were again taken out of the ground and moved to an army garrison further south in the town of Magdeburg.

There they stayed for a quarter of a century, until in March 1970, the garrison was closed down and handed to East German authorities.

Rather than leave the charred bones of the Nazi leader in German hands, a decision was made to destroy the remains and throw the ashes into the river.

All that was left were a few skull fragments and bits of jawbone, which were subsequently divided between the State Archive of the Russian Federation and the Federal Security Service, where they've sat ever since.

Since the moment the news broke, there have been rumours that news of the Nazi leader's death were fabricated and that Hitler had somehow evaded capture and made his way out of Europe.

These whispers were in part fuelled by a relative absence of witnesses. Both of the bodies had been wrapped in blankets before being cremated, and few who personally laid eyes on their lifeless remains survived to provide detailed accounts.

Stars Stripes Hitler Dead2US official army newspaper headline from 1945 (Wikimedia Commons)

Propaganda, anecdotes, and the occasional blurry photograph have provided fertile ground in conspiracy land, leading to suggestions that Hitler had escaped by U-boat to make his way to the foothills of the Andes, only to die decades later.

A study conducted in 2009 only further fanned the flames of conspiracy: a skull fragment from the State archive was subjected to DNA analysis and found to belong not to a 56 year old man, but to a woman aged between 20 and 40.

While there's a possibility it belongs instead to Eva Braun, who was 33 when she died, it was almost certainly not one of Hitler's skill fragments, leaving open the question of whether any of the bones were his.

With the more recent study of the Federal Security Service's bone fragments, we can put those doubts to rest.

Not only do the teeth, crowns, and bridge match the dental work Hitler had done, a scanning electron microscope on the plaque found plenty of evidence of plant matter and no sign of meat.

Hitler was known to be a vegetarian, adding further evidence that these were the infamous Führer's choppers.

Further study of the dental chemistry might also help confirm whether Hitler did indeed bite down on cyanide before shooting himself, helping establish his final moments once and for all.

However, a DNA analysis wasn't conducted, which no doubt will provide something for conspiracy theorists to cling to.

Like all conspiracies, conviction lies not in the strength of the evidence, but in gaps of plausible doubt. Unfortunately, you can bet we haven't heard the end of Hitler's death.

This research was published in the European Journal of Internal Medicine.