The extraordinary tangled love life of the American aviator Charles Lindbergh, the first pilot to fly non-stop across the Atlantic, has been revealed by the three illegitimate children whose existence he kept secret for almost 20 years.

　　They have disclosed intimate details about Lindbergh's affairs in which he fathered children not only by their mother, Brigitte, but also her sister, Marietta, and, allegedly, his private secretary.

　　Dyrk and David Hesshaimer and their sister, Astrid Bouteuil, who are now middle-aged, were born and grew up in Germany without ever being told their father's true identity.

　　They were recognised as Lindbergh's children only in 2003 after DNA tests proved that they were related.

　　In a new book, The Secret Life of Charles A Lindbergh, they reveal how the dashing aviator's 17-year relationship with Brigitte lasted even after he fathered two children with her sister, Marietta.

　　Although Lindbergh had professed admiration for Nazi Germany in the 1930s and supported ideas about eugenics, his passion for the women outweighed any prejudice: the book reveals that both sisters suffered walking disabilities as a result of childhood illness.

　　"I am aware that our actions have tainted the image of an impeccable American hero," said Astrid, 44. "But they also reveal that a man once thought of as emotionless and unattainable was in fact a caring and loving father."

　　Lindbergh was 55 and seemingly happily married to his American wife, Anne Morrow, when he met Brigitte and Marietta at a dinner party in Munich in 1957.

　　He and Anne had six children, their marriage apparently surviving the tragic death of their son, Charles, who at 20 months old was abducted and killed in 1932. Yet according to Rudolf Schroeck, the book's author, over dinner Lindbergh fell for Brigitte, a 31-year-old hatmaker.

　　"The sisters were friends of his secretary, Valeska, with whom he was already embroiled in a relationship," said Schroeck, who drew on more than 150 letters and photographs sent to Brigitte by Lindbergh that were discovered years after his death.

　　Their tempestuous affair ended only with his death in 1974. Although Lindbergh did not live in Germany, he regularly visited Brigitte in Munich and took her to his secret flat in Rome, previously used for trysts with Valeska.

　　When the children were born, he carried on visiting his new family but never told them his real name. "He visited about four times a year for a few days, and made sure they had a wonderful time," Schroeck said.

　　"He took them on trips to the country and told stories of his travels. He never failed to meet his financial duties towards their mother, for whom he built a house.

　　"They were told their father was an American writer, Careu Kent. She made them promise never to mention him to anyone, even friends or family, saying he would not come back if they did."

　　In spite of what Schroeck calls this "stigma of silence", David Hesshaimer, 38, said that his mother seemed content - even after Lindbergh's affair with her sister.

　　"You could see how happy and excited my mother was when she spoke about him," Mr Hesshaimer said. "I could see how intimate they were."

　　Lindbergh's sons by Marietta - Vago, 45, and Christoph, 39 - have remained silent about their parents, in accordance with their mother's wishes.

　　According to Schroeck, Lindbergh also had two children with Valeska but their identities are unknown. None of the three women married.

　　Mr Schroeck said: "Valeska and Marietta have not taken part in the book as they want to honour the vow of secrecy given to Lindbergh."

　　Brigitte's children remained faithful to the same vow until their mother died in 2001, when they decided to speak out about the man they always suspected was their father.

　　"The Lindbergh family were understandably shocked at the news and refused to believe it, particularly as both the Hesshaimer sisters were disabled," said Schroeck.

　　"Lindbergh subscribed to the teachings of eugenics and he believed in breeding healthy children from healthy parents. It was very surprising for his family to learn that he had fathered children to two disabled women who were unable to walk properly."