Authorities have arrested a South Carolina woman they say hid her pregnancy and buried her newborn son in her backyard when he died.

Local media outlets report that 37-year-old Tara Lynn Ostrowski of Rock Hill was arrested Tuesday and charged with illegal conduct toward a child.

Police say Ostrowski hid her pregnancy from everyone, including her husband. Authorities say they learned of the case after Ostrowski in May reportedly confessed what she had done to an informant, who told a mental health employee.

Officials say detectives went to the home and spoke with Ostrowski, who confessed what she'd done and showed them where the baby was buried.

On Wednesday, York County Coroner Sabrina Gast said the baby's death was a homicide and that the baby, born alive, had tested positive for hydrocodone and methamphetamine.