University of Delaware
A debate hall is seen here at the University of Delaware's main campus on October 13, 2010 in Newark, Delaware.Getty Images

Delaware police in United States have arrested a graduate student after hidden cameras in tampon dispensers were discovered around the University of Delaware bathrooms.

Thirty-eight-year-old Javier Mendiola-Soto, a doctoral student from Mexico, has been charged with 21 counts of felony violation of privacy.

Hundreds of women have been reportedly videotaped secretly from the cameras fixed in ladies' bathrooms around the University, said police according to AP News. The cameras were found at three locations around the university, including the Biotechnology Institute, where Mendiola-Soto worked.

Officers have confiscated Mendiola-Soto's laptop, an external hard drive and two mobile phones which led them to the evidence, an estimated 1,500 video files. 

Investigations reveal that Mendiola-Soto had been engaging in these activities on and off campus for at least two years and some 40 victims have been identified by officers.

"It is extremely disturbing that this crime was perpetrated against our community invading the privacy of so many women on and around this campus," said Patrick Harker, the university's President.

The university's Director of Campus and Public Safety, Skip Homiak, called for anyone who thinks that they might have been a victim. A hotline and counselling service has also been set up for victims.

It is yet to be confirmed if the secret videos were uploaded to the internet.