Florida high school teacher Mark Ackett, 49, was arrested last month for secretly recording his female students undressing - but now further charges have been brought

A Florida high school 'fashion' teacher who had been accused of secretly recording female students undressing is now facing even more charges.

Mark Ackett, 49, of Valrico, had been arrested in September on charges of voyeurism but further charges have been added including 267 counts of video voyeurism, 73 counts of production of harmful material of a minor, and 13 counts of possession of child pornography.

Documents have since been released that reveal the former Hillsborough County high school teacher accused of filming students undressing had been doing it for nearly two years.

The fashion design teachers allegedly placed cameras in a changing room to record students.

Ackett often had students change into various clothing designs in a room adjacent to the classroom where he allegedly stashed the cameras.

He was caught by a 17-year-old female student who was undressing in the room and found two cellphones, one of which was recording.

She immediately got dressed and reported the camera to the school, leading to his initial investigation and his arrest.

Ackett, who is married and has two teenage sons, confessed to investigators that the phones were his and he placed them there to record students as they undressed, according to the arrest report.

He resigned immediately after his arrest.

He was caught in September by a 17-year-old female student who discovered two cellphones in the dressing room. Then more former pupils including Emilee Runnels, 18, (above) came forward saying they believe they were targeted as well

Former pupil Chase Burgen believes she was also targeted by Ackett and says 'we thought he was a teacher we could trust. We never got a creepy vibe from him'

Two other students of Ackett have since spoken out following his arrest, saying they feel betrayed by a teacher they loved and trusted.

His former pupil Emilee Runnels, 18, said last year as she was changing in the room where the cellphones were found, she looked around for cameras as a precaution.

'I wasn’t skeptical of him at all. I thought he was such a genuine guy and one of my favorite teachers,' she said to the Tampa Bay Times.

Another student named Chase Burgen, who took Ackett's class last fall, said he betrayed students' trust.

'I think that’s why I and a lot of the girls are just so hurt, because we thought he was a teacher we could trust. We never got a creepy vibe from him,' she said.

She says that he went out of his way to make students feel comfortable.

'We had to talk about body shape and measurements and he always seemed to watch his words and be careful,' Burgen said.

Ackett used to be assistant principal at Bloomingdale High. He became a fashion design teacher at the school last year and also served as a girls track team coach

Both girls believe they were targeted by the teacher.

Runnels said on one occasion she didn't want to try on a dress he made for her. To coax her he said 'But I worked so hard on it for you' and she complied. She added he gave her special attention saying she was like a daughter to him.

'He completely put on a fake face toward so many students. He literally had us all fooled,' she said.

The Hillsborough County Sheriff’s Office believe recording have been made for at least two years, if not longer.

Ackett had worked as a district employee since 1991. He worked at Bloomingdale High as an assistant principal then left to be a supervisor of attendance at a district office.

He returned to teach at Bloomingdale last year and also served as a girls track team coach.

If convicted he could face up to 15 years in prison.