TAMPA - Prosecutors on Tuesday said nude photographs of a 25-year-old former middle school teacher were a necessary part of the investigation into whether she had sex with a 14-year-old student.

Although assistant state attorney Mike Sinacore defended the need for Temple Terrace police detectives to have the photos taken, he did not challenge a request from the defense attorney to prevent their public release.

At a hearing Tuesday morning, Judge Wayne Timmerman signed an order sealing the photos.

Debra Lafave is accused of molesting the student in her Riverview home and in her portable classroom at Greco Middle School. Her attorney, John Fitzgibbons, has filed paperwork indicating he will use an insanity defense at the Dec. 5 trial.

Court records show that the six photographs were taken the day of Lafave's arrest.

``All of these photographs were taken to corroborate the victim's credibility,'' Sinacore said Tuesday. ``We think they did so.''

On June 21, 2004, after the 14-year-old told his mother that he and Lafave had sex, police detectives tape recorded conversations between the boy and Lafave. At the end of the final conversation, he invited her to his home. There, police arrested Lafave and served her with a search warrant.

Reporter Thomas W. Krause can be reached at (813) 259-7698.