A Daegu court on Friday sentenced the older sister of a two-year-old girl found dead at a house in Gumi, North Gyeongsang Province, in February to 20 years in prison on charges of child neglect resulting in death.

The Daegu District Court also ordered the 22-year-old defendant, surnamed Kim, to 160 hours of mandatory counseling and behavioral treatment.

Kim was accused of abandoning her sister at her old residence after moving last August to remarry and causing the child’s death later that month.

At first, the toddler was believed to be Kim's, but the case took a bizarre twist when DNA tests in March revealed that the girl's biological mother was actually Kim's 48-year-old mother, surnamed Seok.

Authorities suspect that Kim and Seok each gave birth to a baby girl around the same time, and that Seok switched the babies so that hers would be raised by her adult daughter. They have yet to discover the whereabouts of Kim's missing daughter.

Seok has also been indicted on charges of attempting to conceal the body of her two-year-old daughter in February, as well as abducting her granddaughter.