(CNN) -- Investigators have found chemical evidence of human decomposition in the trunk of the car connected to Florida mother Casey Anthony, a law enforcement source said Wednesday.
The evidence, discovered at the the University of Tennessee Forensic Anthropology Facility, may help solve the months-long mystery of the woman's missing 3-year-old daughter, Caylee.
The little girl's disappearance has garnered national headlines and has been the nightly fodder of cable TV crime shows.
Caylee has not been seen since early June. Her mother did not report her missing until nearly a month later. Watch more on what the test results mean »
Caylee turned 3 while authorities still searched for her.
Casey Anthony has been charged with child neglect, making false official statements and obstructing a criminal investigation.
Police have said they consider the mother a "person of interest" in her daughter's disappearance.
Grandmother Cindy Anthony pointed police toward her daughter's vehicle. Cindy Anthony told authorities that it smelled as if there had been a dead body in the trunk.
Cindy Anthony has since said that she believes her granddaughter is alive.
"Casey's maintained that she's protecting Caylee, and she's also protecting the family from physical harm. We believe that 100 percent," Cindy Anthony said August 5 .
A spokesman for the University of Tennessee Forensic Anthropology Facility, also known as the Body Farm, said investigators were testing the air found in the trunk of the car for chemical compounds only found in cadavers.
At the time, the spokesman said, "we would not have performed these tests if we didn't think there was something there."
CNN's Christy Lenz contributed to this report.
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