Witnesses have described the moment a man fell 16 metres to his death in a serious accident at a popular Queensland tourist attraction that left another woman in hospital.
About 2pm Tuesday paramedics were called to Jungle Surfing Canopy, which takes tourists on a zip line tour of the Daintree rainforest in Cape Tribulation.
A Queensland Police spokeswoman told news.com.au that the people were known to each other and were tourists from South Australia.
It's believed both tourists fell while on the zip line and were using the same harness.
"They fell about 16 metres," she said.
It is not clear how the pair fell.
The 53-year-old man died at the scene and the woman, aged in her 40s, was taken to Cairns Hospital with serious injuries.
Speaking to 7 News on Wednesday, American couple Samantha Salyer and Joseph Maghe said they had just finished the same section of the tour and watched in horror as the couple fell.
"We got to the fifth platform and there were two couples behind us," they said.
"There was a loud noise, we turned around, one of the lines had snapped and we saw them fall. It shook the entire tree we were on. They hung there, then they both came down at the same time."
A Queensland Ambulance spokeswoman told news.com.au earlier that the woman had an arm/shoulder injury.
A hospital spokeswoman said she was in serious but stable condition.
The ambulance spokeswoman said they were called to a "fall from a height" incident, which refers to a fall of more than 10 metres.
Mossman Police are guarding the scene overnight until workplace health and safety officers arrive in the morning.
A report will be prepared for the coroner.
A Cape Tribulation resident told the Courier-Mail there were delays on the Daintree Ferry following the incident as motorists were forced to give way to emergency services.
"I saw ambulances and fire crews rush past. This won't be good for tourism," the unnamed man told the publication.
The Jungle Surfing tours have been in operation since 2003. Linking five platforms with zip wire cables spanning up to 95 metres, the attraction website says that the highest point is over 16 above the ground.