Md Kamal Hossain had apparently agreed to give a confessional statement to a court on Sunday after two days of police grilling but later changed his mind.
The court sent him to jail, Sub-Inspector Anisur Rahman told bdnews24.com.
He said Kamal had been produced in the Dhaka Metropolitan Magistrate’s court following his petition to give a statement.
The judge gave him the time to think over the decision and he, finally, backtracked, Rahman said.
A group of people had sexually harassed several women on the campus during the Pahela Baishakh celebration on Apr 14 last year.
Police spotted eight of the suspected molesters on CCTV footage, published their photos and announced a reward of Tk 100,000 for clinching information.
But on Dec 13, police submitted their final report, closing the case without naming any of the suspects.
Kamal, a vegetable vendor, was later arrested from Old Dhaka on Jan 27.
Police said the father of two had shaved off his beard after the incident to conceal his identity.
They also said he had confessed to the crimes during the preliminary interrogation.
Investigator Detective Branch SI Dipak Kumar Das has sought the revival of the case.
A Women and Children Repression Prevention Tribunal will hear his petition on Feb 13.