Lohan, who was enrolled at California`s famous Betty Ford Center, is currently serving three months of court ordered treatment for a probation violation. She was supposed to stay at the rehab until earlier this month when she moved to another facility.
Dailystar.co.uk reports, the switch came after an alleged clash with an employee, who was later fired for giving details about the incident to the media.
It has now been revealed that officials have launched a probe into the Betty Ford clinic, although the agency has not confirmed whether the investigation is linked to Lohan`s case.
Lohan`s mother Dina has since spoken out about her daughter`s stay at Betty Ford, insisting staff at the center were "fabulous" and "really helped" the actress.