A major search has resumed for a woman missing in far north Queensland after she was seen in distress while swimming in a river north of Cairns.
The 54-year-old tourist went missing in the waters of Mossman Gorge at 2pm on Friday.
Boats and aircraft were involved in Friday's search before it was called off after dark.
Queensland Police's Sergeant Ed Lukin said the woman was seen in distress as she was swept downstream in the Mossman River.
"Of course, we hold out hope that we will find this woman alive and safe, however, there are serious concerns for her welfare," he told media on Friday.
He said the waters in the area were dangerous and prone to rising fast without warning, with seemingly placid conditions failing to reveal strong undercurrents.
"Swim at your peril in the far north (of Queensland). In these kinds of conditions it can't be understated how dangerous some water courses are," Sgt Lukin said.
Police are in contact with the woman's next of kin.
The woman was believed to have been with friends before she went missing.
Emergency services also deployed drones and divers in rescue operations which resumed at 6am local time on Saturday.
