A 38-year-old doctoral student from Mexico was arrested for secretly videotaping hundreds of women in bathrooms at the University of Delaware, Wilmington, officials said.

Javier Mendiola-Soto was detained and charged with 21 privacy offences July 1. Court documents state that concealed cameras were found in tampon dispensers across the university. The cameras were found in ladies' washroom at three locations including the Biotechnology Institute where Mendiola-Soto worked, and in a unisex disabled toilet, reports Sky NEWS.

According to the police, Mendiola-Soto might have been hiding cameras in restrooms for at least two years. Authorities who inspected the videos were able to identify around 40 victims. They said they will not disclose the names of women being filmed.

Skip Homiak, executive director of UD campus and public safety, said Saturday that Mendiola-Soto, told the campus police he downloaded 1,500 separate videos taken from the secret cameras.

Mendiola-Soto is being held at the Young Correctional Institution in Wilmington on a $42,000 secured bond. According to federal immigration authorities, he would remain in jail even after making the cash bond, Homiak said, reports Delaware Online.

Homiak said that it was still unclear how Mendiola-Soto hid the cameras in the women's bathrooms. "We don't know the answer to that. The cameras had to physically be removed and downloaded each time he placed them in the bathroom," he said.

The state attorney general's office maintains they have enough evidence to prosecute the case and will not try to identify any additional victims for prosecution purposes.

Homiak said that those who think they may have been a victim can reach out to investigators if they want.