LINDSAY LOHAN's ELIZABETH TAYLOR biopic is under investigation by two U.S. acting labour groups after she collapsed with exhaustion last Friday (15Jun12).

The Mean Girls star had a health scare after she was reportedly found passed out in her California hotel suite. Lohan later explained she was simply exhausted after "working 85 hours in 4 days" on her comeback movie Liz & Dick.

Two other crew members allegedly left the production due to exhaustion, and now bosses at International Alliance of Theatrical Stage Employees (IATSE) and SAG-AFTRA have launched a probe.

IATSE division director Mike Miller says, "The IATSE is on top of the situation on the set of Lifetime's Liz and Dick. We have had union representatives on the set since last Friday and will continue to monitor the hours and working conditions there.

"We take very seriously the safety and wellbeing of our crews, and are dedicated to seeing that they are protected from hazardous working conditions."

Meanwhile a SAG-AFTRA spokeswoman tells TheWrap.com, "We have thoroughly investigated this matter and our business representatives have visited, and will continue to visit, the set of Liz & Dick. We have spoken with representatives from the company and they are fully aware of their contractual obligations. We will ensure that all applicable penalties will be paid."

06/21/2012 6:44