Fairfax also reported that police were called to the campus on Friday morning after reports of a group of boys in their underwear running up the gully to the edges of the school, armed with eggs.
Police could earlier be seen parked outside the main entrance, while security guards were posted on every gate.
The initial streaking prank happened just after midday on Wednesday and police rushed to the school after receiving a call from ambulance staff.
"There was a collision with a bike and a student on the school grounds. The student has suffered moderate injuries and has gone to hospital," police earlier said.
While the victim's family have addressed the event as a prank that "has gone a bit wrong" and wanted the incident to blow over, Hamilton Boys' High School principal Susan Hassall hoped charges would be laid.
"I think we need to send a strong message to young students that such reckless behaviour won't be tolerated," she earlier told the Herald.
Waikato road police senior sergeant Pete van de Wetering said police are reportedly looking at possible charges.
"Police will be considering charges - there must be some accountability given the risk of injury, which has been demonstrated in this case.
"While we understand it was a prank and a bit of spirited excitement by the girls, if there has been an injury, like there was in this case, there must be accountability."
Police officers are believed to have spoken with the girls, who were all 17-year-old girls from Waikato Diocesan School for Girls, on Thursday.
Waikato Diocesan principal Mary Curran confirmed school authorities were helping police and the school was still interviewing the girls over the incident.
"This is the first step in an official process."
Curran will then give her report to the Boards and they will decide on the action that will be taken.
