Yonsei University has denied allegations that questions for one of its early admissions exams were leaked online, saying there will be no retest. 

The prestigious school in Seoul issued the statement Sunday, a day after some ten-thousand students took a natural science essay test there. 

The university acknowledged that proctors had mistaken the time of the exam in one room and distributed exam papers at 12:55 p.m., more than an hour before the 2 p.m. start time, instead of 1:55 p.m. as scheduled.

The papers were collected 15 minutes later, but some of the students reportedly posted some of the questions on online communities for prospective test-takers. 

A university official said the school will ask the police to look into the matter to determine whether any questions were indeed leaked.