Famed biographer Kitty Kelley‘s explosive new unauthorized book about Oprah Winfrey claims there is a "world of secrets" surrounding one of the world’s most powerful women. In Oprah: A Biography, Kelley spills the beans on Winfrey’s sex life, her history of sexual abuse as a teen and the identity of her father. "The secrecy knocked my socks off," the celebrity biographer tells PopEater.com.

Among the revelations in the book:

• Kelley debunks the rumor that Oprah is a lesbian but claims that she is really "asexual"
• Oprah once dated Entertainment Tonight host John Tesh

• Her relationship with her mother is so strained that she doesn’t have her daughter’s direct phone number

For the full story, go to PopEater.com.