Three illegitimate children of Charles Lindbergh, the first pilot to fly non-stop across the Atlantic, have come forward to reveal details of his extraordinary love life.

The aviator 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, 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 Lindbergh’s 17-year relationship with Brigitte lasted even after he fathered two children with her sister, Marietta.

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

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 Rudolf Schroeck, the book’s author, 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, Lindbergh 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.”

According to Schroeck, Lindbergh also had two children with Valeska but their identities are unknown.

None of the three women married.

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

“Valeska and Marietta have not taken part in the book as they want to honour the vow of secrecy given to Lindbergh.”

Lindbergh was known to have professed admiration for Nazi Germany in the 1930s and supported ideas about eugenics.

However, despite this, his passion for the women outweighed any prejudice.

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.”

The Lindbergh family refused to believe the news of Lindbergh’s secret family, particularly as both the Hesshaimer sisters were disabled.

“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,” said Schroeck.

Lindbergh became a pariah within 15 years of becoming the most celebrated man on earth for his solo flight to Paris in 1927.

He was cast as an anti-Semite and Nazi sympathiser after making several visits to Nazi Germany to report on the Luftwaffe for the US military in the 1930s.

Public opinion turned against him when he accepted a medal from Hermann Goering and recommended that the US negotiate a neutrality pact with Hitler.

In 1941, he accused “the Jewish race” of being behind the drive for America to enter the war.

“We cannot blame them for looking out for what they believe to be their own interests, but we must look out for ours,” he told a rally.

Lindbergh spent his final years on the Hawaiian island of Maui, where he died of cancer in August 1974.

His complicated love life remained a secret until the Hesshaimer siblings came forward after their mother’s death in 2001.

Despite the scandal, they speak fondly of their father in the book.

“People may wonder about his treatment of his wife and my mother, but the fact that we exist testifies to the fact that he was simply a man – not a hero,” said Astrid.