Two years before her divorce from Prince Charles, Princess Diana had an abortion during an affair with a married London art dealer, according to a new book, "The Real Diana," released Tuesday. In the book, author Lady Colin Campbell says the Princess of Wales became pregnant in 1994 by Oliver Hoare, an art dealer and Middle Eastern expert. Campbell cites one unidentified source: an earl's daughter who was a friend of Diana's. Quoting the friend, Campbell writes that Diana "freaked right out" when she learned she was pregnant by Hoare. "She wanted the baby. 'Suppose it's a girl,' she said, distraught at what she knew she had to do," Campbell says. "What Diana 'had to do,'" the friend says, "was to have an abortion... So Diana, tearfully and in distress, sacrificed the baby she wanted," Campbell writes. Buckingham Palace declined comment on the book.