"I abused and betrayed the trust of another sibling, my sister, my blood sister," he said. "I'm sorry, Mo'Nique. I'm sorry."
Imes' reason for appearing on Winfrey's show to apologize to Mo'Nique was to reunite their family. He said he wants to overcome the past and amend broken bonds with his sister.
Though the actress has discussed her brother's molestation in past interviews, she hasn't responded to requests for comment sent to her publicist Monday. Mo'Nique did not participate in the interview but gave Winfrey the green light to conduct it saying that her brother's confession and apology could help others in similar situations.
Mo'Nique's parents made an appearance on the show and said that the incident has been "a heartbreaking thing to accept."
Mo'Nique received the supporting actress Academy Award in March for her role in "Precious: Based on the Novel 'Push' by Sapphire."
AP contributed to this report.