Is it illegal to perform genital modification surgery on an intersex child?

The legality of genital modification surgery is unclear.  Generally speaking, guardians have a duty to act in the best interests of their children, and can provide consent for medical treatment on a child (unless the child has capacity to consent).  
 
In October 2016, the UN Committee on the Rights of the Child made a series of recommendations to the New Zealand Government on the rights of intersex children. These recommendations have been passed on to the Director General of Health.