A missing German backpacker's abandoned van has been found after she disappeared while travelling solo in the outback.
Carolina Wilga was last seen in the general store in the WA wheatbelt town of Beacon about noon on June 29, about 300km northeast of Perth.
The 26-year-old, who had been travelling and working in Australia for about two years, told friends she intended to explore regional WA.
Her disappearance triggered a nationwide search amid concerns for her safety.
Police found Ms Wilga's Mitsubishi van on Thursday about 150km from Beacon.
"The vehicle was located abandoned in the area, in the northeast Wheatbelt region of Western Australia, and is believed to have suffered mechanical issues," a spokesman said on Thursday.
Ms Wilga was not found.
The temperature in Dalwallinu, near Beacon, dropped to 2.6C overnight, with more cold weather on the way.
"The search to locate her is continuing, with additional resources being deployed to the area," police said.
Investigators previously said they did not believe Ms Wilga was the victim of a crime.
"It's certainly unexplained her disappearance and we are taking it very seriously," Detective Senior Sergeant Katharine Venn said.
"Her family are understandably distraught, very worried, as any of us would be with a young family member the other side of the world, missing in such unusual circumstances."
Det Snr Sgt Venn described the region as "very remote".
"The actual town site is very small and when you travel out there are some very picturesque spots and some quite inhospitable, rocky terrain," she said.
Ms Wilga has a slim build, with frizzy or curly long, dark blonde hair and brown eyes, with several tattoos, including symbols on her left arm.
She last had contact with friends on June 29 and had travelled through the towns of Toodyay and Dowerin, southwest of Beacon, earlier in the day.
Ms Wilga's mother previously pleaded for anyone with information about her daughter to contact authorities.
"Carolina is still sorely missed. If anyone has any information, please contact the police. Please keep your eyes open!!!", Katja Will said on a WA Police Facebook post.
A Facebook page named Help Find Carolina Wilga has been set up.
Karroun Hill Nature Reserve, at more than 300,000 hectares, is the largest nature reserve in the southwest of WA.