The 57-year-old Tesh says he and the 56-year-old Winfrey dated while working in local news in Nashville, Tenn.
The book "Oprah: A Biography" claims Tesh and Winfrey didn't just date, but lived together for a short period in the 1970's. It goes on to say Tesh abruptly ended the relationship one night when he noticed their contrasting skin colors and couldn't handle being in an interracial relationship.
Tesh has not commented on the book's explanation for their split, but did tell "Entertainment Tonight" he and Winfrey remain good friends.
Winfrey's representatives did not immediately respond to a request for comment.
"Oprah: A Biography," written by Kitty Kelley, hits stores Tuesday. Kelley has written unauthorized biographies on celebrities, including Jackie Kennedy, Frank Sinatra and Nancy Reagan.