A third lawsuit has been filed by an extra against the producers and director of “Apt Pupil” for allegedly filming him in a nude shower scene without prior notice or prior consent.

Ben Scott Baker, in a complaint filed in Los Angeles Superior Court, claimed he was ordered to strip naked once on the set at Elliot Middle School on April 2 and was told he would be fired if he left or refused to perform nude.

The suit also alleges that a still photographer took indecent pictures of the boys “for no legitimate purpose related to the filming” and that the incident caused Baker to go from being a straight-A student to getting grades as low as a C.

The suit seeks unspecified damages.

Defendants include Phoenix Pictures Inc., TriStar Pictures Inc. and Sony Pictures Entertainment.

“These accusations are outrageous and completely without merit,” a Phoenix Pictures spokeswoman said.

Other defendants include Happy Endings Prods., JD Prods., Bad Hat Harry Prods., director Bryan Singer and producers Kenneth Kokin, Jane Hamsher and Don Murphy.

Previous suits were filed on behalf of extras Devin St. Albin and David Stockdale.