Rihanna lost her "best friend" when she split from Chris Brown.

The We Found Love singer has revealed it was "humiliating" when the R&B star violently assaulted her in February 2009 and says she was in a "dark" place following their break up in an emotional new interview with Oprah Winfrey.

In floods of tears, Rihanna told the chat show host: "It was embarrassing. It was humiliating. I lost my best friend.

"I was resentful. I held a grudge. I was dark."

The emotional superstar added: "I am super duper terrified of the pedestal that comes with fame."

The teaser for the special edition of Oprah's Last Chapter shows the 24-year-old Bajan beauty opening up about the infamous domestic abuse incident and promises more details about the status of her current relationship with Brown (23).

TV mogul Winfrey has praised the candour and vulnerability the pop princess showed while filming the episode together in Barbados.

Winfrey admitted: "I thought she would have been kind of a bad-ass kind of a rocker hard-edge woman - nothing could have been farther from the truth.

"She was thoughtful. She was very emotional. She was vulnerable."