Update: Lindsay Lohan failed more than one drug test

44984, LOS ANGELES, CALIFORNIA - Wednesday September 15th, 2010. Lindsay Lohan and gal pal Eliat Anschel leave the All Saints boutique on Robertson Boulevard via the back door. Photograph:  David Tonnessen, PacificCoastNews.com

We knew that Lindsay Lohan would be undergoing court-mandated drug tests and since her release from jail, she can not fail any of them. But TMZ.com is reporting and confirming that Lindsay Lohan has failed a recent drug test and under the conditions of her probation, Lindsay will serve 30 days in jail if there was a positive shown during a drug test.  Yikes!

UPDATE: TMZ.com is reporting that Lindsay Lohan failed multiple drug tests and one tested positive for cocaine and the other tested positive for another unknown substance.