The man is described as a clean-shaven solidly built Maori or Polynesian aged around 20 with short black hair.
Mr Hermann said he was driving what appeared to be an older model white four-door or five-door hatchback car.
"We want to hear from anyone who may have seen something suspicious in the area at the time of the attack or who has information on the identity of the attacker," he said.
It's not known which school the girl came from.
Police said it took some time before the young victim was able to find the courage to report what had happened to authorities. Mr Hermann said that police were working with the school concerned and Child, Youth and Family.
The schoolgirl is understood to be highly traumatised by the incident.
"The key now is to ensure this girl gets the help she needs to work through this and that police obtain information from the public to help catch the offender responsible," said Mr Hermann.
HELP WANTED
Police need help in identifying a man who allegedly raped a Hamilton teenage girl in Durham St on February 27.
A clean-shaven, solidly built Maori or Polynesian about 20, driving an older white hatchback car, is sought.
Call Det Sgt Robbie Hermann, Hamilton Central Police on 07- 858-6200 or Crimestoppers on 0800-555-111.Hamilton police seek help to trace man driving old white car near Elliott Park.