Police are holding out hopes a 30-year-old woman last seen running into bushland along an outback highway a week ago is still alive, as they continue to search an area north-west of Alice Springs.
Angie Fuller was last spotted along the Tanami Road, 15 kilometres west of the intersection with the Stuart Highway, on Monday by her boyfriend.
A search and rescue operation comprising of 20 police officers, as well as helicopters and a drone, has been underway since Wednesday.
Acting Superintendent Rob Engels on Sunday said the search-and-rescue team had already scoured 240 square km of scrubland looking for her.
"We believe Ms Fuller is alive. There are certainly water sources in the area that she can access," he said.
"Our experts to date tell us it is survivable at this time."
Boyfriend assisting police with inquiries
Police were notified of Ms Fuller's disappearance on Wednesday, with no further sightings of her since Monday.
Superintendent Engels said Ms Fuller's boyfriend was the last person to see her and was assisting police with their inquiries.
His car was searched while in the search area.
"The circumstances of her disappearance are ongoing and will form part of our investigation," he said.
"At this point our main concern is finding Ms Fuller.
"We believe she and her boyfriend had run off into the bush where she was last seen, and we are hoping she has gone to ground in there and is accessing water and giving us an opportunity that we will find her."
Superintendent Engels would not comment on why Ms Fuller was along the Tanami Road on Monday.
Police first alerted the public to Ms Fuller's disappearance on Friday, urging the public to contact them with information as to her whereabouts.
On Saturday, authorities made a renewed plea for information, urging anyone travelling along the Tanami Road between 10pm Saturday, January 9 and 9am on Sunday, January 10, to contact police.
Police described Ms Fuller as of Asian appearance, approximately 165 centimetres tall with long black and purple hair.
At the time of her disappearance, she was wearing a black Nike singlet and a cream skirt.