Andrew Spanswick, a spokesman for the family of James Lee DiMaggio, said rumors have circulated on social media that DiMaggio fathered the children and that it was "a little strange" that the suspect named the girl's paternal grandmother as his life insurance beneficiary.
Lora Robinson, DiMaggio's sister and lone survivor of his immediate family, collected DNA from her brother and wants samples from Hannah Anderson and her brother to determine paternity, Spanswick said. She has not yet asked for the samples but intends to at a later date.
"The biggest issue is, I think, that Lora wants closure on the case," Spanswick said. "As Lora has heard these rumors, she would like to confirm whether they are true or not."
Anderson family spokeswoman Stacy Hess said DiMaggio didn't meet the children's father and mother, Brett and Christina Anderson, until Christina was six months pregnant with Hannah. Investigators used Brett Anderson's DNA to confirm the identity of 8-year-old Ethan Anderson, whose remains were found in the rubble of DiMaggio's burned home, Hess said.
Brett Anderson finds the suggestion that DiMaggio fathered the two children "disgusting," Hess said. She said the family had not yet received a DNA request directly from DiMaggio's family and declined further comment.
Spanswick said the family's interest in paternity tests, which was first reported by KGTV in San Diego, has been "blown way out of proportion" by the media.
"It's just for clarity," he said.
DiMaggio, 40, was like an uncle to the Anderson children and Brett Anderson's best friend. Hannah was rescued Aug. 10 when FBI agents killed DiMaggio in the Idaho wilderness, ending a massive search that spanned much of the western United States and parts of Canada and Mexico.
Investigators say DiMaggio escaped with Hannah and killed 44-year-old Christina Anderson and her son, whose bodies were discovered after DiMaggio set fire to his home Aug. 4 in Boulevard, a tiny town 65 miles east of San Diego.
DiMaggio named Hannah's grandmother, Bernice Anderson, as the sole beneficiary of his employer-issued life insurance policy, making her eligible to receive $112,000, according to Spanswick, who believes the money was intended for Hannah.
San Diego County Sheriff Bill Gore has called Hannah "a victim in every sense of the word." He has declined to discuss a possible motive and investigators haven't publicly addressed other aspects of the case, including why the family went to DiMaggio's home, how Christina and Ethan Anderson died, the nature of letters from Hannah that were discovered in DiMaggio's home, and how Hannah was treated in captivity.
DiMaggio used a timer to set the fire, giving him a 20-hour jump on authorities, said Jan Caldwell, a spokeswoman for the San Diego County Sheriff's Department.
Caldwell declined to say if Brett Anderson's DNA was used to identify his son's remains. Authorities have said they extracted DNA from the boy's bone marrow.