Rihanna has said that she lost her "best friend" when she broke up with Chris Brown.

The singer opened up about the relationship for an Oprah's Next Chapter interview, which will be screened on August 19 at 9pm ET on OWN.

Speaking about her high-profile split from Brown in 2009 after he assaulted her, Rihanna said: "It was embarrassing. It was humiliating. I lost my best friend."

She continued: ''I was resentful. I held a grudge. I was dark.''

Rihanna also admitted that she is "super duper afraid of the pedestal that comes with fame", stating: "It's amazing how lonely you can feel."

It was reported last month that Rihanna and Brown shared an evening together on a yacht, but Brown later denied the claim.