AceShowbiz - Lindsay Lohan is reportedly at the center of a police probe amid allegations a staff member at California's Betty Ford clinic was assaulted during the actress' stay. The "Mean Girls" star was moved from the rehab center to another unit last week to complete her court ordered treatment for violating her probation stemming from a DUI arrest.

But her relocation has been mired in controversy - it emerged on Tuesday, December 21 that officers in Palm Desert, California are investigating after a female member of the Betty Ford staff was assaulted during an altercation with Lohan and some pals, according to TMZ.com.

Cops received a call at 1.03 A.M. on December 12 for "hand-to-hand battery" - but a source tells the website Lohan was not the perpetrator of the incident. The troubled actress insists she didn't strike the first blow and merely pushed back at the unnamed member of staff after she was "unfairly" lectured about arriving at the home after her curfew and ordered to take a drug or alcohol test, according to TMZ.

The website claims Lohan yelled, "Take your hands off of me" as the drama escalated, and then "pushed back" against the woman.

Update: In a statement to TMZ, Betty Ford officials say, "Regrettably, on December 21, 2010, one of our employees violated strict confidentiality guidelines and laws by publicly identifying patients in a media interview and by disclosing a privileged document. The employee has been terminated by the Betty Ford Center."