In a terse statement released Wednesday, the 39-year-old singer denied a former brother-in-law's claim that she has a "secret" 18-year-old daughter.
"I do not have a child and all allegations saying so are false," Jackson said in a statement released to the syndicated
"Access Hollywood" TV show.
A call to Jackson's publicist by The Associated Press Wednesday wasn't immediately returned.
On Friday, Young DeBarge, the brother of Jackson's ex-husband, James DeBarge, said Jackson and his brother had a child named Renee that was living with Rebbie Jackson, Janet's oldest sister.
"James and the Jackson family kept everything real close, real tight," Young DeBarge said on New York radio station WQHT, known as Hot 97.
Jackson and James DeBarge, a singer in the former R&B family group DeBarge, were married for three months in 1984, when Jackson was just 18.
Jackson secretly married Rene Elizondo Jr. in 1991. They separated in 1999. She is now dating Jermaine Dupri.
Young DeBarge, 28, is promoting his debut album.