A woman who was convicted of killing her own eight-year-old daughter out of anger over discord with her live-in partner was sentenced to 22 years in prison by an appellate court Thursday.

The 44-year-old woman, whose name was withheld, was arrested early this year for murdering her daughter, who was sleeping at their home in Incheon, west of Seoul, by blocking her nose and mouth on Jan. 8.

The girl's body was found by the woman's common-law partner one week later. The woman reportedly told police she committed murder after getting angry because her partner did not comply with her request for financial support and loves only their daughter very much.

A district court sentenced the woman to 25 years in prison in May, but the Seoul High Court commuted the sentence to 22 years, citing her deteriorating health conditions.

"Her crime is very grave considering the motive and circumstances. But she is in very poor health, as her left knee was amputated due to complications from diabetes and underwent several surgeries due to rotting skin," the appellate court said, explaining the reason for commutation.

According to court records, the woman gave birth to her daughter while living with her common-law partner without divorcing her marriage husband, although neither made her birth registration nor sent her to a kindergarten or school.

The woman is said to have simultaneously made her daughter's birth and death registrations on the same day after her death.

Meanwhile, the woman's live-in partner was found dead about one week after her arrest. (Yonhap)