A paramedic has stabilised a 38-year-old woman who broke her hip when she fell eight metres in King Country's Luckie Strike cave.
Search and Rescue co-ordinator Phil Bell said Jane Furket was with two companions when she fell into a stream about 2.40pm.
She suffered a broken hip and lost three teeth.
A companion managed to pull her from the stream and cover her in a survival blanket before coming out to raise the alarm, police said.
Mr Bell said Ms Furket was an experienced recreational caver and was a member of the Nelson Caving Club.
The accident happened about 1100 metres into the cave which was 15km from the Waitomo township.
Mr Bell said it appeared Ms Furket had unhitched herself from a traverse line on a slippery ledge just prior to the fall.
An advanced paramedic from the Westpac Rescue Trust was now with Ms Furket and has stabilised her, but she was suffering from cold due to the fall into the stream.
Specialised heating equipment was en route to the injured woman, Mr Bell said.
The rescue was considered quite technical due to the high traverse lines and narrow passage ways and Ms Furket was being brought out in a stretcher suspended about eight metres above floor level.
Mr Bell said it was likely to be about midnight before she would be brought out.
Twenty-five trained cave Search and Rescue staff comprising caving guides from the Waitomo area and recreational cavers from the Waikato region, were involved in the rescue.
Luckie Strike - off Waipuna Rd, about 20 minutes drive west of the village of Waitomo Caves - has a reputation among cavers as one of the most physically demanding and beautiful caves in the country.
The woman is lying about one hour's travel into the cave, which requires traversing, climbing, crawling, abseiling and squeezing through wet and dry passages and up waterfalls.
"She is about an hour from the surface - which could translate into five hours back to the surface," said a spokesman for the rescue coordinators.
"It's a moderate scramble for a cave - it's not very easy to walk through," the spokesman told NZPA
"It's going to be pullies and ropes and hard work until midnight."
Last year, Motueka doctor Michael Brewer found himself in a similar situation -- injured and trapped 400m underground in the Middle Earth cave under Takaka Hill near Nelson.
It took nearly three days and a highly complicated rescue effort involving about 50 cavers to extract him.
