Detective Sergeant Beatson said Kaitaia police were treating the attack seriously.
"We understand some passers-by stopped to see if the victim was okay during or immediately following the incident. However, because the victim was upset and disorientated members of the public were unable to provide her with assistance. We want to speak to these people, and any other witnesses who saw the incident unfold."
Police say the hat was a distinctive black "Monster" snapback cap with a number of fluorescent M's around the peak and brim and they would like to hear from anyone who has seen it.
Anyone with information can contact Kaitaia Police on (09) 408 6500 or call Crimestoppers anonymously on 0800 555 111.
- nzherald.co.nz