LAS VEGAS (AP) — An autopsy performed on the body of a child found in an Illinois garage is unable to determine cause of death.

St. Clair County, Illinois, Coroner Calvin Dye Sr. says the autopsy was performed Friday but the body was too decomposed to immediately determine how the child died. Dye says further testing will be necessary on the bones, but it may not be for another couple of weeks.

A woman in Las Vegas called police Monday night and said her daughter’s body was in the garage behind a vacant home in Centreville, Illinois, near St. Louis. Police found the body Tuesday morning. Police believe the child was killed in 2013 in nearby Belleville, Illinois, when the girl was 6.

The child’s father is jailed in Las Vegas on sex trafficking and other charges. Charges have not been filed in the girl’s death.