Police said the unknown offenders had damaged the support structures of the historic flagpole on Te Maiki Hill, as well as damaging the flagpole itself, and graffitied the surrounding area.
The damage is believed to have happened sometime between Sunday, January 30 and Monday, January 31.
"This area is now unsafe, and has been fenced off while the Department of Conservation works to restore the structure and its surrounds, so it can be safe and enjoyable for the public once more," police said.
Anyone with information is asked to contact police on 105 and quote file number 220202/8881.
The attack has disappointed local hapū who, for the first time in living memory, will be unable to raise Te Kara (the United Tribes flag) on Waitangi Day.
Kororāreka Marae chairwoman Deb Rewiri said the attack on a wāhi tapu and internationally significant site was disappointing.
In the previous attack the misspelled word "fredom" was spraypainted on the post but Rewiri urged people not to jump to conclusions about who was responsible or what their motives could be.
Another symbol, a crossed-out NWO, is thought to refer to conspiracy theories claiming a secretive elite is planning a totalitarian New World Order.
It was also not clear whether the pole had been cut only halfway through because the attackers had been disturbed, or whether they intended it to fall at a later time, possibly when people were present.
