A German backpacker slipped and smashed his shoulder and mouth on wet rocks as he tried to rescue an Australian woman who fell into a freezing river on the Milford Track on Monday.
Police hold grave fears for the 22-year-old Sydney woman as the search continues today.
The woman was hiking with her Australian partner when she was caught in the Pompolona Creek about 3pm on Monday and was swept into the Clinton River.
Sebastian Keilholz, 20, from Bamberg in Germany, was with the couple - he called them "Jessica" and "Jean"- when they reached the creek. The river was so inflated from pouring rain that they could not see the normal stepping stones, he told the Sydney Morning Herald.
Jean, 26, and Sebastian crossed first, before Jean went back to help Jessica cross. But as they crossed together, the river overpowered Jean mid-stream and he fell. He managed to grab a rock to halt his slide until Sebastian could reach him and pull him out.
Jessica was also mid-stream when she was overwhelmed by the force of the water.
"We told her to stay there, where she was, but she was so in panic, that she also fell into the stream" Sebastian told the Sydney Morning Herald.
"Jean was saved so I ran as fast as I could to help Jessica. I fell two times, but I stood up and ran.
"The rocks were so slippery, that I fell again, two times on my shoulder and then on my mouth. My teeth were broken, blood came out of my mouth and Jessica was gone."
They activated an emergency beacon, which was picked up by the National Rescue Co-ordination Centre about 6pm Monday, but poor weather prevented a helicopter rescue. Helicopter searches yesterday morning and afternoon found no sign of her.
Sebastian ran on to Mintaro Hutt, where he gathered other hikers to return to the creek and rescue Jean, who was suffering from shock.
Sebastian was upset about the condition of the river crossing.
"I'm angry that they didn't tell us that there are no bridges and I'm angry that I couldn't help her.
"I would never go (on) such a dangerous track if I knew that there are no bridges. I hope they will find Jessica in the next days."
Police said another group of walkers had crossed the same stretch without difficulty about two hours before them.
A crew from Southern Lakes Helicopters spent yesterday afternoon searching for the woman, but stopped searching when it became dark.
Senior Sergeant Fairley said Te Anau police and Rescue Co-ordination Centre New Zealand would reassess their search plans on this morning, but he stressed conditions were difficult.
Police were working with Department of Conservation staff and LandSAR volunteers. Jean is understood to be in shock, but helping the rescue team. Jessica's family are on their way to New Zealand.
Pompolona Creek was high after recent rain and weather conditions were poor. Rain continued yesterday afternoon and MetService issued a severe weather warning for the area. Between 170mm and 210mm of rain was expected this morning, with "significant spillover rai" about the headwaters of Otago lakes and rivers.
The Milford Track Great Walk is closed to guided walkers from May 1 to October 27 but is open to independent trampers with reduced facilities.