Police in the small Utah state town of Roosevelt thought that a riot was taking place the first time that they saw a haka being performed.

Not knowing what was happening they used pepper spray and batons on the spectators performing New Zealand's native Maori challenge following a high school game of American football, including a dozen from a single family, one aged 4.

An investigation by the police of Roosevelt, 230 kilometers (140 miles) east of Salt Lake City, cleared their own officers of wrongdoing in the October incident.

But the Utah branch of the American Civil Liberties Union said the police report was "anything but objective," and noted the police failed to consider a video of the haka or statements from 15 witnesses who said they did not feel threatened by the performance.