The 'Double Jeopardy' star filed a police report in Tennessee last month, after a mechanic found a wireless GPS tracking device on her vehicle, reported Us magazine.
In legal documents, Ashley reportedly told cops she believed Wynonna was responsible for the GPS and an investigation launched by authorities traced the device back to a private investigator, who claimed to be "working for" the musician.
The papers reveal the sisters are currently embroiled in a custody dispute over Wynonna's teenage daughter, who Ashley is said to have custody of, and the actress claims the device was "placed there in order to track their movement".
Kelley has denied any involvement in the scandal and authorities appear to have put the case on hold, as it is currently listed as inactive.