Short answer: No. You need at least 5% deposit, plus money for fees and inspections.
No. Every bank in New Zealand requires some deposit. The smallest deposit you can get is 5% through the First Home Loan scheme, and even then you still need money for legal fees and inspections. There is no way to buy a house with zero deposit.
Setup: John has no savings but his parents own their house outright.
Option: Some banks accept a family member's house as additional security.
Reality: This is called a guarantor loan. John still needs to prove he can afford repayments.
Risk: If John cannot pay, the bank can force sale of his parents' house.
Conclusion: It is possible with family help, but it is not "no deposit" — it is using someone else's equity.