A person charged three times for entering tracks closed in the Waitākere Ranges due to kauri dieback could be fined up to $60,000.
Auckland mayor Phil Goff said the prosecution - the first of its kind following the unprecedented track closures - reflected the "seriousness of the issue".
"While most Aucklanders understand the need for temporary track closures to help stop the spread of dieback, those individuals who flout the rules with no regard for the damage they cause need to be held to account."
The Waitākere Ranges Regional Park has become a hotspot for the tree-killing kauri dieback disease, with a 2018 survey showing it had spread to around 20 per cent of kauri in only a decade.
In May 2018, Auckland Council closed high-risk tracks in the Waitākere Ranges Regional Park to the public to protect forested areas from the further spread of kauri dieback disease, after Auckland iwi Te Kawerau a Maki initiated the process by placing a rāhui, or ban, over the area.