Police are using drones and a plane to search for a German tourist who has been missing for more than a week in Central Australia and had been interested in hiking the hot, remote local trails.
Monika Billen, 62, was reported missing in the Alice Springs area yesterday, after she failed to return to her motel.
Northern Territory Police said she was last seen leaving the Desert Palms Resort on Barrett Drive at 10:30am on January 1, via CCTV.
She had been due to check out of the resort on January 5.
"We understand Ms Billen may have had some interest in walking the Larapinta Trail or local bush trails," Acting Superintendent Pauline Vicary said.
"Police have been and will continue to conduct enquiries as to Ms Billen's possible movements since leaving the resort, and have deployed our Remote Piloted Aircraft to popular walking tracks around Alice Springs."
Drones are also being used to search popular walking tracks around the region.
She is described as being of Caucasian appearance, of slim build, with short grey hair, and was last seen wearing a red chequered long-sleeve top, denim knee-length shorts and a bright red backpack.
CCTV footage identified at least five motor vehicles passing the resort on Barrett Drive at the time Ms Billen walked out on January 1.
Two of the motor vehicles were taxis and three were civilian motorists who may have seen or picked up Ms Billen.
Police urged anyone who may have seen Ms Billen or who have any information as to her whereabouts to contact them on 131 444.
Hiking hazardous during summer heat
Walking tracks in the Alice Springs area have proved hazardous to tourists in the past, particularly during summer months when temperatures can exceed 45C.
On New Year's Day, the day Ms Billen was last seen, three adults with a toddler from the Philippines suffered heatstroke after attempting a walk in the West McDonnell Ranges.
On January 11 last year, a 33-year-old American tourist died after taking a wrong turn on the Larapinta Trail, on a day when the mercury reached 42C.
In February 2017, two German tourists were found dead in Trephina Gorge, outside Alice Springs.
During an inquest into the deaths last year, one of the victim's sons said he hoped improvements to signage throughout the park would prevent a similar tragedy from occurring and that he would like to see mobile GPS applications promoted to hikers visiting the region.