"Three of the alleged incidents occurred off-site, in all of the incidents the recruits were off-duty," Fraser said.
An investigation into the four incidents was ongoing.
Stuff has reported a recruit had been involved in an off-campus drinking session which resulted in police property being damaged.
A recruit, who did not want to be named, said there had been an incident in which a male recruit inappropriately touched another recruit in the college bar, Stuff reported.
"As part of a redevelopment project, a bar located at the college is due to close next week.
"The redevelopment has been planned for some time and once finished will provide a new learning centre and cafe, where limited alcohol sales will be available."