A 26-year-old woman was violently assaulted outside an out-of-control 18th birthday party in Dobson early on Monday morning.
Greymouth police today appealed for witnesses to the assault, on the footpath outside the Brunner Workingmen's Club, in Omapere Street, to come forward with information.
Detective Kirsten Norton, of the Greymouth CIB, said the woman was assaulted by a group of three or more people; both men and women.
St John ambulance staff called to Dobson to treat the victim, alerted police to her injuries.
Ms Norton would not say whether the woman had been sexually assaulted.
She was treated at Grey Base Hospital for "moderate" injuries.
Ms Norton said everyone involved in the incident had been drinking.
"We have already spoken to some people who were at the party, but there are certainly more people to be spoken to who will be able to give us a lot more information in regards to what happened."
The party was closed down about 1.30am after complaints of loud noise and disorder.
Police estimate between 150 and 200 people were at the celebration.
Information about the assault can be passed on anonymously to Crimestoppers by phoning 0800 555 111.
- The Greymouth Star