FORT WORTH, Texas (AP) — A Texas medical examiner says the deaths of the young daughters of an internationally known pianist were most likely due to asphyxia.

The Fort Worth Star-Telegram ( ) reports the Tarrant County medical examiner's office released the autopsy reports of 1-year-old Michela Kholodenko and 5-year-old Nika Kholodenko on Thursday. Their mother, Sofya Tysgankova, has been charged in their deaths.

Vadym Kholodenko, a winner of the prestigious Van Cliburn International Piano Competition, discovered his daughters' bodies March 17 when he arrived at the Benbrook home the girls shared with their mother so he could take them to school. Arrest affidavits for Tysgankova, say the girls were found dead on beds.

The 31-year-old Tysgankova has pleaded not guilty to two counts of capital murder. She remains in the Tarrant County Jail with bail set at $2 million.