Ellen Degeneres' mother regrets not believing that she had been sexually abused by her stepfather.

The 61-year-old TV chat show host's mom initially ignored her when she claimed her partner had groped her breasts - claiming to be looking for ''lumps'' - when she was just 15 years old and now she has to live with the guilt of not supporting her through the traumatic time for the rest of her life.

Speaking to NBC, Betty said: ''I know now that one of the hardest things to do is speak up after being sexually abused. I love my daughter, and I wish I had the capacity to listen to her when she told me what happened. I live with that regret, and I wouldn't want that for any other parent. If someone in your life has the courage to speak out, please believe them.''

The comedienne first claimed that her stepfather had abused her during an interview on Netflix's 'My Next Guest Needs No Introduction With David Letterman' earlier this month.

She said the man - who she did not name - initially pretended to be checking her boobs for potential lumps after her mother Betty had been diagnosed with breast cancer.

Ellen recalled: ''He told me when she was out of town that he'd felt a lump in her breast and needed to feel my breasts because he didn't want to upset her, but he needed to feel mine.

''Again, because I didn't know about bodies, I don't know that breasts are all different and... Anyway, he convinced me that he needs to feel my breasts and then he tries to do it again another time, and then another time. He tries to break my door down, and I kicked the window out and ran cause I knew it was going to go more to something... and I didn't want to tell my mother cause I was protecting her and I knew that would ruin her happiness.

''I'm angry at myself because, you know, I didn't... I was too weak to stand up to... I was 15 or 16. It's a really horrible, horrible story and the only reason I'm actually going to go into detail about it is because I want other girls to not, you know, ever let someone do that... I should never have protected her. I should have protected myself and I didn't tell her for a few years and then I told her.

''And then she didn't believe me and then she stayed with him for 18 more years. And finally left him because he'd changed the story so many times.''