Sergeant Richard Panting, of police Search and Rescue, said Nicola Hedley (36), known as Nic, had not been seen since she left a party at a Harington Point property, near Dunedin, about 3am on Sunday.
``The rest of the party thought she went out to her tent, but when she hasn't arisen from her tent the next day they became concerned and began a search.
``We believe she was intoxicated,'' Sgt Panting said.
She was reported missing on Sunday night.
Police and about 40 LandSAR volunteers, a qualified search and rescue dog and friends and family of Ms Hedley scoured areas surrounding Otakou marae and neighbouring land until about 10pm yesterday.
A police spokeswoman said the search would resume early this morning.
Search and rescue teams from the Catlins, Balclutha and North Otago would join the search today, Sgt Panting said.
Ms Hedley's cousin Craig Duncan, who lives in Scotland, said he was ``worried sick'' about his cousin.
Ms Hedley's clothing at the time she vanished was ``not ideal'' for the weather conditions, Sgt Panting said.
``She was wearing a long-sleeve dark top with a logo on the front of it, a hoodie, and possibly a bum bag.''
On Sunday the temperature dropped to 6degC and 11.6mm of rain fell, mostly in the morning.
Ms Hedley was 157cm tall, of average build, and had dark hair which was long on one side and short on the other, Sgt Panting said.
She also had a piercing on her collarbone and tattoos of stars behind her ear.
A post on Facebook page Dunedin News by Ms Hedley's friend Holly Coory said it was ``out of character'' for Ms Hedley not to return home.
