Reports that first-year students were made to simulate a rape scene as part of their induction are to be investigated by the National University of Singapore (NUS).
The sexualised games were part of a forfeit during an orientation camp, according to the reports.
Students, who said they felt pressured to take part, were also asked to answer a range of personal sexual questions.
NUS promised "strong disciplinary action" against anyone responsible.
"NUS does not condone any behaviour or activity that denigrates the dignity of individuals," it said in a statement on Tuesday. "These activities are neither approved nor endorsed."
The university said students were meant to feel "safe, secure and respected" at all times and it was "very disappointed" that such activities had surfaced.
'She looked uncomfortable'
The optional student-run orientation camps are designed to welcome first-years and integrate them into university and campus life.
But students speaking to news outlet the New Paper (TNP) said they had felt pressured to take part in increasingly sexualised activities.
One of the forfeits allegedly required a pair of male and female first-year students to re-enact a rape scene between a young man and his younger sister.
"The girl had to lie on the floor, and the guy... then kicked open her legs and did push-ups while lying on top of her," Kim, a 19-year-old student told TNP.
"The girl looked very uncomfortable and covered her face throughout the whole thing."
'Safe, secure, respected'
"It's high time this issue is underscored and something done of it," an NUS student who attended an orientation camp for two days told the BBC.
"Those who argue that people should just 'lighten up' miss the fundamental point about basic respect."
The student added that there were "cheers with crude references to male genitalia" involved in the camp that he attended.
However, Olivia Azali, an NUS graduate student said there were no such activities involved in the camp she attended as a first-year student.
"There was nothing as gross," she said. "Ours was pretty mild."
Reports of inappropriate activities at freshman camps at various universities surface each year in Singapore.
In 2014, NUS made headlines after complaints that a male student was stripped to his shorts before being blindfolded and bound with tape, as female students licked whipped cream off his neck.
The university took the top spot in the Times Higher Education Asia University Rankings published this year.