Is This Janet Jackson's Secret Daughter? Star's Ex-Mother-in-Law Says She Has DNA Test to Prove It

Etterlene DeBarge, the mother of Jackson's ex-husband James DeBarge, tells Inside Edition she thinks she's found the truth.

Janet Jackson's former mother-in-law claims the star has a secret daughter — and she says she can prove it.

The singer, 50, gave birth to a son in January, reigniting rumors over whether she'd given birth to a baby girl 31 years ago.

Read: More Questions Arise Over Janet Jackson's Alleged 'Secret Daughter' With First Husband

Now Etterlene DeBarge, the mother of Jackson's ex-husband James DeBarge, tells Inside Edition she thinks she's found the truth.

In an exclusive interview that will air in full on Thursday, she recalled her conversation with Jackson about the alleged pregnancy three decades ago.

"So you asked her if she was pregnant?" Inside Edition's Les Trent asked DeBarge.

"I told her she was pregnant; I didn't ask her," DeBarge said. "I said, 'Girl, you pregnant. Look how fat you're getting.' She just laughed it off. She never denied it."

DeBarge said she has been contacted by several women over the years claiming to be Jackson's secret daughter. But one day, she heard from a woman she thought could be a match.

"I told her, 'The proof is in the pudding. Let's go get a DNA test,'" she said.

The DNA test results showed "the probability of relatedness if 96.7 percent," she said.

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The woman, who lives in Philadelphia, is now 31, which makes her the right age. But is she really Janet Jackson's secret daughter?

Jackson has not responded to Inside Edition's request for comment.

Tune in to Inside Edition Thursday for the full interview.

Watch: Janet Jackson Gives Birth to a Baby Boy