Some school students are playing an alarming game to see who can sleep with the most people - and the younger the conquest, the better.
Dr Kim McGregor, director of Rape Prevention Education, fears the ball season could lead to more young people being at risk of taking part in the game.
She said some students from a couple of Auckland high schools had told her team about the "game" but she wasn't sure how many schools were involved.
She urged parents and schools to educate young people on respectful sexual relationships, bystander responsibility, how to stay safe and that the legal age of consent was 16. She said a key message, too, was sex with anyone who was drunk or "stupefied" should never take place.
McGregor said parents should tell their kids they must tell an adult or authority figure if they heard anything about the game.
Secondary Schools Association president Patrick Walsh said he, too, had heard about the game.
"Any victims need to report it to police," he said.
Nick Laing, programme supervisor at Auckland Sexual Health Service, wanted to encourage any young people with questions or concerns about sex to speak to someone they trusted.