The billboards of Maori Party co-leader Debbie Ngarewa-Packer were defaced over the weekend, with some spray painting over her moko kauae.
In a post on her Facebook page, photos show four of her billboards were targeted - with three in particular having white paint sprayed over moko kauae.
A fourth one had a crude word written across it.
In her post, Ngarewa-Packer said racism wasn't about how looked, "it's about how people assign meaning to how you look".
"Whakapapa is our strength, as is replacing hate with love. I'm so grateful to all our whānau out there eradicating racism and promoting #believeinMaori."
The graffiti angered her supporters.
One wrote, "So disgusted to see this Debbie .. you are a powerhouse wahine and your every move brings about progress towards the changes we absolutely need in our society. Kia kaha wahine ma.. they are feeling the winds of change blowing past them."
Another woman wrote, "It's really embarrassing to be a pakeha when I see this," while another supporter said, "Shocking behaviour but not surprising. Head high Deb."