Lindsay Lohan under investigation for attack on rehab staff member

Police said they were called to Betty Ford centre in California on December 12, after reports of an assault.

US media reported that the incident occurred when staff confronted the troubled star after she returned late to the clinic.

The Mean Girls star was ordered to the rehab programme in October after failing a court-ordered drug test.

"The victim desires prosecution," Riverside County Deputy Sheriff Herlinda Valenzuela reportedly said.

The case is still under investigation, however, Betty Ford spokesman Russ Patrick said the staff member who had made the complaint had now been sacked for breaking patient confidentiality.

The employee conducted an interview with celebrity website TMZ on Tuesday.

Lohan is due to be released from the clinic next month. She was convicted of drink-driving in 2007 and failed a random drug test this year, causing a judge to commit her to the rehab centre.