A peeping Tom was caught filming a resident in a student dormitory at the Nanyang Technological University (NTU) yesterday.
The fourth-year student from Hall of Residence 16 was nabbed by students after he was spotted filming the resident in the shower.
The resident saw a smartphone above the cubicle wall while he was bathing at 1am.
He rushed out to confront the suspect, who locked himself in a cubicle, school newspaper The Nanyang Chronicle reported.
The resident,who did not want to be named, then called for help and a few hall residents caught hold of the suspect when he came out of the cubicle.
The students went through the alleged voyeur's smartphone and discovered 66 videos of male students showering saved in the suspect's phone.
He had tried to delete the videos while hiding in the cubicle, but they were found in a folder of recently deleted items, the Chronicle said.
Mr Paul Lee, Hall 16 student president, called campus security, which reported the matter to the police.
They stood watch over the suspect, who had tried to escape, he told The Straits Times.
Police said they received a call for assistance at 2.07am. A 24-year-old man was arrested for "possession of obscene material", police said.
Investigations are ongoing.
Mr Lee, 22, a second-year engineering student, said: "Such acts will not be tolerated in my hall. I hope this will be a stern warning to other voyeurs."
He also warned hall residents to be alert when showering.
This is the second incident of a peeping Tom at Hall 16 this year.
Another suspected voyeur was caught, also by students, in the first quarter of the year.