Actress Daniele Watts' plans to speak to students at her alma mater in California have been postponed by law school officials after she was charged with lewd conduct for allegedly having sex in her car.

The 28 year old, who appeared as slave girl Coco in Django Unchained, had been booked to return to the University of Southern California on Wednesday (22Oct14) to discuss issues regarding "race, sexual expression and civil rights law", according to a post on Watts' page.

However, the event was pulled late on Tuesday (21Oct14) after Los Angeles prosecutors filed the misdemeanour charges against the actress and her boyfriend, Brian James Lucas, following a police encounter in September (14), when she was allegedly caught straddling her partner with her breasts exposed.

A spokeswoman for Usc insists the cancellation has nothing to do with the accusations and reveals the guest lecture had to be rescheduled for a larger venue at the Usc Gould Law School due to high demand, according to the New York Daily News.

Watts and Lucas, who deny the accusations against them, face up to six months behind bars if convicted of the lewd conduct charges.

They are due to face the counts in court next month (Nov14).