Riverside County Deputy Sheriff Herlinda Valenzuela said police were called to the facility in the early hours of December 12 and conducted a misdemeanor battery investigation involving Lohan and an unidentified member of the center's staff.
"The victim desires prosecution," Valenzuela said, but she added that detectives have not yet completed their investigation. No further details were available.
Lohan, 24, voluntarily checked into the Rancho Mirage, Calif.-based clinic in October, after failing a random drug test linked to her probation on a 2007 drunk driving charge. She has already spent about two weeks in jail and three weeks in another rehab center this year.
TMZ.com identified the alleged victim as a chemical technician who told the celebrity news site that she was asked to perform a breath test on Lohan for alcohol. The actress pushed her, the woman claimed, and later pulled a telephone from her hand, resulting in a sprain. TMZ said the woman was called in by Betty Ford security after Lohan and her two roommates returned from a night of partying past curfew.
But Lohan's estranged father, Michael Lohan, told rival outlet X17 that her daughter returned late from a hair appointment, and that the woman grabbed her arm.
Source: Spina