Dog the Bounty Hunter Says His Father — Who Physically Abused Him — Is Not His Biological Parent

Duane "Dog the Bounty Hunter" Chapman is opening up about a shocking family secret he discovered.

In PEOPLE's exclusive clips from the 68-year-old reality star's appearance on The Dr. Oz Show Dog reveals that he learned several years ago that his father — who was abusive — is not his biological father.

"My little sister was a couple of years younger than me and she had a very bad infection," Dog, who was joined by fiancée Francie Frane, says in the clip. "She was a nurse and she knew that she was not going to make it. So just before she passed away, she said, 'Oh, by the way, I want to tell you that dad is not your father. He is Paula's, Mike's and mine, but he's not really yours and maybe that's some of the reason he beat you more."

In a second clip, Dog elaborates to host Dr. Oz about the brutal physical abuse he endured from his dad — who has since died — while growing up.

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"Well, my father, who I just found out last year was not my blood daddy, was in the Navy back in the day and there's a scripture in the Bible that says, 'Spare the rod, spoil the child.' That's Old Testament repercussion," says Dog. "My father would spank me so hard with a belt or a piece of board, and he'd pull my pants down. Number one, that was humiliating. I lean over a couch and just go to wailing.

"I couldn't even shower at school because I was so embarrassed of the bruises," Dog adds.

RELATED VIDEO: Dog the Bounty Hunter on Learning His Dad Wasn't His Biological Father

Dog, who says in a third exclusive clip he was beaten "daily" by his father, also shares that the reason for the abuse began to add up once he learned about his true lineage.

"When I found out that he wasn't my dad, a lot of things that he used to say, 'I gave you your name,' 'I'll beat the savage out of you,' come to find out. A lot of things started coming full circle," he tells Dr. Oz. "Oh, no wonder."

RELATED VIDEO: Dog the Bounty Hunter Details His Father's Abuse

"But the last thing I'd like to say, I used to arrest people, I'd say, 'Why do you do this, man?' 'Well, I don't know who my dad is, Dog,' and I used to feel so bad. And I don't know who my dad is either. But I still love my daddy," says Dog. "If there wouldn't be how he raised me, I wouldn't be the man I was today. So, I kind of get over those excuses that my people have. 'Oh, I don't know my dad, and you don't understand.' Yeah, Big deal."

"Do I want to find my dad? No," he adds. "Do I have a dad? Yes, and his name is Wesley Chapman."

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Dog's family revelation comes after his wife Beth Chapman, who was diagnosed with stage II throat cancer in 2017, died in June 2019 at the age of 51.

Last March, Dog revealed his relationship with Frane, a 51-year-old rancher from Colorado. PEOPLE confirmed the couple's engagement in May.

Dog's appearance on the Dr. Oz Show airs Monday, May 3. Check local listings.

If you are experiencing domestic violence, call the National Domestic Violence Hotline at 1-800-799-7233, or go to thehotline.org. All calls are toll-free and confidential. The hotline is available 24/7 in more than 170 languages.