Magen Fieramusca, 33, was arrested on two counts of kidnapping and a tampering with evidence charge, the Austin American-Statesman reported. The evidence was identified in arrest records as a human corpse, according to the newspaper.
An unidentified source told KHOU that Fieramusca will be charged with murder. Authorities did not immediately confirm the report.
Police said Broussard and her daughter, Margot Carey, were last seen on the morning of Dec. 12. Family members told NBC News that a body believed to be Broussard's was recovered Thursday from the trunk of a car in Jersey Village on Thursday. Her mother, Tammy Broussard, told the news network her granddaughter was recovered in good condition.
Austin police confirmed Friday that an infant was found Thursday night in Harris County and that DNA testing was underway to confirm her identity, KEYE-TV reported.
Update 7:57 a.m. EST Dec. 20: A family member confirmed to NBC News early Friday morning that Broussard's body was found Thursday night and the baby is alive.
Tammy Broussard, Heidi Broussard's mother, told the network that a body found in a car trunk in a Jersey Village neighborhood is likely her daughter's.
The medical examiner will need to confirm the body's identity, she told NBC News, and said police told her her granddaughter, Margot Carey, is in good condition.
Original report: Law enforcement agencies investigating the disappearance of a Texas mother and her newborn missing one week swarmed a Houston-area home and removed an infant from the premises late Thursday, multiple news outlets reported.
Craig Cummings with the Texas Department of Public Safety confirmed to KPRC the search of the home Thursday near Jersey Village is connected to the missing mother and child.
KRPC also reported that a medical examiner's van arrived on scene late Thursday, and a reporter for KTRK tweeted that a body was removed from the home.
According to NBC News, Cy-Fair Volunteer Fire Department public information officer Lt. Daniel Arizpe confirmed a 1-month-old infant was found safe at the home just before 11 p.m., but the child's identity has not been released.
Arizpe said a call from Child Protective Services for a welfare check at the address prompted the investigative activity. The child, who was transported to a local hospital, had no obvious injuries, the network reported.
KTRK also reported a car parked in the rear of the home is registered to an acquaintance of Broussard's.