Lindsay Lohan is being investigated for an alleged battery against a female staff member at her rehab clinic.
Authorities in Riverside County, California said officers were called to the Betty Ford Centre over an incident on December 12 involving the Mean Girls star.
A female member of staff reported having a dispute with Lindsay and told police she wanted to press charges. No arrests have been made and detectives are continuing to look into the case.
Troubled Lindsay, 24, was receiving treatment at the Betty Ford Centre near Los Angeles since late September.