O.J. Simpson's former attorney publicly announced he had agreed to take over as the star's representative after her legal Shawn Holley Chapman quit earlier this month (Jul10).
Chapman walked away from the Mean Girls star on the day she was sentenced to 90 days in jail for violating probation on a 2007 DUI arrest.
Shapiro, who lost his son to a drug overdose, insisted Lohan check into his own sober living facility before starting her prison time on Tuesday (20Jul10).
But according to TMZ.com, the lawyer is no longer representing Lohan - even though she adhered to his rules by entering rehab in Los Angeles last week (begs12Jul10).
No reason for Shapiro stepping down was given as WENN goes to press.
The actress has been ordered to surrender to authorities at Beverly Hills Superior Court on Tuesday morning (20Jul10) to begin her jail time.