Northern Territory police are conducting an extensive search in areas around Nitmiluk National Park to try to find a Victorian tourist who has not been seen for three days.
Daymon Ness, 30, had been travelling alone and arrived in Katherine from Darwin by hire car on Monday.
NT Police said Mr Ness arrived at Nitmiluk the next day sometime after 1:00pm.
Police believe he then went for a walk on one of the Nitmiluk trails alone.
Parks and Wildlife staff, together with police, are searching the national park.
Daymon's father William Ness said his son had texted a friend on Tuesday, telling them he was going for a walk around Katherine Gorge.
"He sent some pictures to his cousin in Germany on Monday night and texted a friend on Tuesday about 11 o'clock to say he was about to go for a walk at Katherine Gorge," he said.
"And that was the last communication anyone had.
"If anyone sees him, please get in touch with police. We're hoping all that's happened is he has had a fall and he's injured.
"If anyone was at Katherine Gorge on Tuesday and saw him, please get in touch with police. He's very friendly and very approachable.
"We would really appreciate any help because we are really concerned."
Mr Ness is described as a Caucasian male, with a thin build, around 190 centimetres tall, with dark brown hair, hazel eyes and was last seen wearing a black top, green/grey pants and red shoes.
Police are appealing to anyone who may have seen Mr Ness to contact them on 131 444, or Crime Stoppers on 1800 333 000.
