A group of more than 50 New Zealand Olympians, doctors and sport administrators has called on the government to review guidelines on transgender athletes in community sports, saying they ignore female athletes' rights and undermine fairness and safety.

The group raised their concerns in an open letter addressed to New Zealand's sports minister, Chris Bishop, Prime Minister Christopher Luxon and Foreign Minister Winston Peters.

The letter called for an urgent review of Sport New Zealand (SNZ) guidelines which encourage transgender athletes to compete in amateur-level sport in the gender they identify with and not need to prove or justify their identity.