Air and land searches for a German tourist believed to have been missing in Central Australia for almost two weeks have been called off.

NT Police announced on Saturday night they would cease searching bushland near Alice Springs for 62-year-old Monika Billen after five days of searching returned no results.

Ms Billen had been in Alice Springs on holidays, but has not been seen since New Year's Day.

Police said they had "exhausted all locations of interest" but would "continue to conduct enquiries" about the disappearance.

"In the past five days Northern Territory Police have covered vast tracks of land via aerial and land searches," Superintendent Pauline Vicary said.

"Unfortunately, despite our efforts no further evidence has been found to indicate Monika is still out there.

"The last physical sighting we have for her is the Emily Gap and surrounding area, which we have thoroughly searched."

Police search the Emily Gap area near Alice Springs for missing German tourist Monika Billen, 62. ( ABC News: Katrina Beavan )

Tracing Monika's last movements

Ms Billen was captured on CCTV leaving the Desert Palms Resort in Alice Springs, about 10:30am on New Year's Day.

She failed to check out of the hotel on January 5 and missed a flight she was scheduled to take to Darwin.

Despite failing to check out of the room, she was not reported missing until January 8 — a week after she had last been seen.

During a search of Ms Billen's hotel room, police discovered brochures for popular walking tracks, including the 223-kilometre Larapinta trail.

This led them to believe she had undertaken a hike, despite temperatures in Alice Springs on the day she went missing hitting 43.5C.

Following reports of sightings from the public, police focused their search for the missing tourist on Emily Gap, a rock formation only 13 kilometres from Alice Springs.

The search of the area included the use of helicopters, drones, motorbikes, dogs and horses, but it ultimately failed to find a trace of the missing woman.

NT Police have used drones to scour hostile terrain in search of Ms Billen. ( Supplied: NT Police )

Confusion over sightings

On Friday afternoon, police made a last-ditch attempt to get information from the public.

"We are very concerned we are getting very little information come in from the Alice Springs people in relation to whether they've seen Monika or not," Acting Superintendent Pauline Vicary said on Friday.

"Just don't assume that other people are going to tell us and you don't need to.

"Particularly, there are eight vehicles that drove past her on Barrett Drive on the first [of January], none of those people have contacted us.

"We are urging you — please contact us so we can have a conversation, you may have seen something and not even realised it."

Several appeals to the public did result in multiple tips, which led to the focus on Emily Gap.

Police said it was the last confirmed sighting of the 62-year-old, despite reports she had been picked up by a local resident and dropped off at the Olive Pink Botanical Gardens on January 2.

"We are trying to clarify some information in relation to the timing that Monika was dropped off at Olive Pink," Superintendent Vicary said on Friday.

"That may have actually been earlier than anticipated now."

Despite her vanishing seemingly without a trace, police said they did not believe Ms Billen's disappearance was suspicious.