MB Satish, a junior college administrator, told the BBC the school decided to use the technique to curb cheating on an "experimental basis".

Satish also stressed that "there was no compulsion of any kind".

"You can see in the photograph that some students were not wearing it," he told the BBC. "Some who wore it removed it after 15 minutes, some after 20 minutes and we ourselves asked them to remove it after one hour."

According to the Times of India, officials from the department of education ordered the school to stop the measure after they saw the images online.

One official told the Times of India it was "an inhuman idea in the examination hall".

"This is inhuman and a civilised society will never accept such an idea," the official said. "There are traditional ways of managing students and preventing malpractice in the examination hall and the college can resort to them."

It's not the first time teachers have used such a technique.

Earlier this year, a high school in Mexico was heavily criticised after doing the same thing.