‘Of course – but not the sexual side. I always assumed he was Klara’s father, but she never spoke a word about such things. For all her love of mischief, she could be very discreet when she wanted. Anyway, she thought everything would be all right when she returned to their apartment in Munich.’

‘But it wasn’t?’

‘In the summer of that year something happened – something by the name of Martin Bormann, the devil himself. Geli called me in Vienna. I had never heard her in such a state. She told me she was in mortal danger. Bormann had found out something and was blackmailing her, threatening to tell Hitler about the baby. He wanted to know more. Where was the baby? Who was looking after it?

‘He kept pestering her – threatening her and intimidating her. And he was trying to get her into bed. Whenever Hitler was away, she had to steer clear of Bormann. But still he would appear at her door, cajoling and demanding, trying it on.

‘Geli knew she was in grave danger but her greatest fears were for the baby. She told me that the child had to be moved to safety – she was terrified someone would tell Bormann about Braundorf. And so I contacted the Riegers and told them they were no longer safe and that they would have to leave Austria. Maria wasn’t happy. As a good Catholic, she did not like the idea of living in Lutheran northern Germany. But in the end, she had no choice, and they moved to Kossertheim in Brandenburg. It was easy enough for Matthias to find work as a lowly-paid teacher and they quickly settled in.

‘I had also moved to northern Germany at that time. I visited them often – but I knew that we were never really secure as long as Bormann was alive.

‘I was desperately worried for Geli – and tried to get her away from Munich. I even begged her to leave the country – go to England or America. But she would not listen. Not at first. Finally I persuaded her and she said that yes, she would come to me in Berlin. Her plan was to leave Munich while Uncle Alf was away on one of his electioneering tours. On September 18, 1931, she called me and told me she was packing a small bag and would be leaving that evening. Hitler had gone away and the housekeeper, Frau Winter, would be out at the cinema. It was the perfect time. She said she would get the train – and that she was longing to see me. Those were her last words to me. Bormann stopped her with a bullet.’

‘You are certain it was him, not suicide?’