In September 1931, however, she died of a gunshot wound in his apartment. The weapon used was Hitler’s own pistol, though Hitler was apparently not present at the time and the death was recorded as suicide, though those who knew her said she was the happiest, least suicidal person they had ever met. The death was not completely hushed up, but it was played down. The would-be Führer was grief-stricken by her death, but could not be blamed; he was away on a campaigning trip at the time of death. This much is known. But there is something else that not even Hitler knows: Geli had a baby a few months before she died.

The words brought Wilde up with a jolt. The implication was obvious and astonishing. He continued reading.

There is much else that was never told and the world never knew, including the true circumstances surrounding Geli’s death and the reason she died. These facts, if they were to come out, would have seismic repercussions for the Nazi hierarchy and Germany as a whole.

Later, when we are out of the range of microphones, I will tell you more of what is known – their days out when he’d watch her swimming naked in pools and lakes, his jealousy when he thought there might be other men in her life – particularly his driver Emil Maurice and a music teacher in Austria.

At times it all became too much for the girl. She got claustrophobic because Uncle Alf – that’s what she called him – didn’t let her out much. But late in 1930, early 1931, she managed to get away to Austria for three or four months. However, that absence had less to do with claustrophobia and more to do with the pregnancy she was desperate to keep secret from him and everyone else. The only person in Germany who knew the truth was her mother, who kept house for Hitler at his other home, a modest mountain chalet named Haus Wachenfeld before it was expanded and renamed the Berghof.

Geli’s mother warned her that Uncle Alf could not be distracted from his political work by family matters. He was on the brink of power and nothing must stand in his way. Whether or not he was the father, she must have an abortion. Otherwise, there would be gossip and his standing would suffer because he portrayed himself as a man married to his country. Even if Geli denied he was the father, the fact that she lived with him at 16 Prinzregentenplatz in Munich would set tongues wagging. In Catholic Bavaria, the idea that a 42-year-old man had fathered a child by his 22-year-old niece out of wedlock would have caused massive damage to his electoral chances. He has sold himself – or been sold by Goebbels – as a man who has sacrificed his own domestic happiness for the good of the nation, forgoing the love of a wife and family for his love of Germany. And his image of self-sacrifice has worked – the fact is, Hitler is beloved by women more even than by men. That love would have turned sour in a heartbeat if whispers of an illegitimate child leaked out.