Julie Andrews will reveal in her memoirs that she was born as the result of a brief affair her mother had while married, the Sunday Times of London reported.
The "Mary Poppins" star will disclose that she was conceived in a passionate romance between her mother, Barbara, and "a man by a beautiful lake near Walton-on-Thames."
At the time, Andrews' mother was wed to woodwork teacher Ted Wells, the man Andrews grew up loving as a father.
She also recalls in her memoirs the day she met her biological dad in 1949 when she was 14, according to the Sunday Times.
"I remember feeling an electricity between us that I couldn't explain," Andrews writes.
The beloved "Sound of Music" actress, 72, has kept the secret of the affair for 58 years.