Staff at popular public schools are turning sleuth to catch parents who try to cheat out-of-area enrolment rules.

One school caught seven families using the same enrolment address. Another uncovered a forged signature. And one found out that a student's family was sharing their address with friends after spotting a fake tenancy agreement.

Schools are spending precious time catching out parents that try to cheat the enrolment rules. Credit:Tamara Voninski

Public schools prioritise students in their catchment zone, but some are so popular due to strong results or good reputations that there are few places left for out-of-area applicants, prompting some parents to go to drastic lengths to pretend they are local.

In one case at highly sought-after Strathfield Girls' High, senior staff door-knocked a home to check a prospective student's address, only to find the people who lived there didn't know the applicant and had been there for years.