Talk show host Oprah Winfrey has denied rumors she's gay.

In an upcoming interview with ABC's Barbara Walters, the 56-year-old media mogul says she's “not even kind of a lesbian.”

“I'm not a lesbian,” she says in the special. “I'm not even kind of a lesbian.”

Winfrey goes on to say that persistent rumors that she and gal pal Gayle King are lovers annoy her because it means “somebody must think I'm lying.”

“Why would you want to hide it? That is not the way I run my life.”

Winfrey called King “the mother I never had … the sister everybody would want … the friend that everybody deserves.” (The video is embedded in the right panel of this page.)

A new source of speculation appeared in April, when Kitty Kelly released Oprah: A Biography.

In the 544-page book, long-time friend and author Erica Jong is quoted having said: “I would not be surprised if Oprah is gay. If she is, she is. It certainly fits.”

“[Oprah boyfriend] Stedman is probably gay or neutral, but they have a bond,” Jong added. “Her being gay would be the right reaction to the sexual abuse she says she's suffered and the mistrust she's always had of men.”

Appearing in 2009 on the The Howard Stern Show, openly lesbian comedian-actress Rosie O'Donnell said, “I think they [Winfrey-King] are the emotional equivalent of a gay couple.”

A Barbara Walters Special: Oprah, The Next Chapter airs Thursday at 9PM.