Former U.S. Sen. Edward Brooke declined to comment Friday about whether he had an affair with Barbara Walters in the 1970s.
"I have had a lifetime policy and practice of not discussing my personal and private life, or the personal and private lives of others, with the notable exception of what I wrote in my recently published autobiography, `Bridging the Divide: My Life,"' he told The Associated Press in a phone interview from Miami.
A relationship with Walters wasn't mentioned in his book, the 88-year-old former senator from Massachusetts told the AP.
His memoir was published in 2006.
In an appearance on "The Oprah Winfrey Show" scheduled to air Tuesday, Walters shares details of her relationship with the married Brooke that lasted several years in the 1970s, according to excerpts of the show provided to the AP.
A moderate Republican who took office in 1967, Brooke was the first African-American to be popularly elected to the Senate. Walters said he and she knew that public knowledge of their affair could have ruined their careers.
At the time, the twice-divorced Walters was a rising star in TV news and co-host of NBC's "Today" show, but would soon jump to ABC News, where she has enjoyed unrivaled success. She said her affair with Brooke, which never before came to light, had ended before he lost his bid for a third term in 1978.
Brooke later divorced, and has since remarried.
Walters, 78, will appear on Winfrey's show to discuss her new memoir, "Audition," which covers her long career in television, as well as her off-camera life. On "Oprah," Walters recounts a phone call from a friend who urged her to stop seeing Brooke.
"He said, 'This is going to come out. This is going to ruin your career,"' then reminded her that Brooke was up for re-election a year later. "'This is going to ruin him. You've got to break this off."'
Winfrey asks Walters if she was in love.
"I was certainly -- I don't know -- I was certainly infatuated."
"I was certainly involved," Walters says. "He was exciting. He was brilliant. It was exciting times in Washington."
Brooke served two full terms from 1967 to 1979, taking on the populist causes of low-income housing, increasing the minimum wage and mass transit. He received the Presidential Medal of Freedom in 2004, an honor only 21 U.S. senators have received.