An indigenous group has joined the search for a 62-year-old Austrian man who went missing in a national park in Paraguay three weeks ago.
Wilhelm Wabnegg was last heard from on 2 May when he was setting off for the Cerro León hills in the Defensores del Chaco national park.
His motorhome was found on 10 May but there was no trace of Mr Wabnegg.
Fifteen members of the Ayoreo tribe are now searching their ancestral land for Mr Wabnegg.
Officials said that the Ayoreo, who have inhabited the Gran Chaco area between Bolivia and Paraguay for centuries, stood a better chance than anyone of finding Mr Wabnegg.
The national park measures 780,000 hectares and the area around Cerro León 80,000 hectares and has diverse wildlife such as jaguars, ocelots and cougars.
The Ayoreo will spend three days searching for the Austrian, who has been travelling through South America in his motorhome since November.
Officials had already called off the search five days ago saying they had done all they could but after the offer of help by the Ayoreo they decided to try one last time to locate the missing Austrian.
Mr Wabnegg posted photos of his adventures on a blog. In it, he said his plan was to be on the road for 14 months.
He described setting off in Chile and travelling south to Patagonia. Tired of the "cold and wet weather" he then drove back north again stopping in national parks, sometimes picking up people he met along the way.
In his vintage Mercedes motorhome, he also made it to Peru, Bolivia and finally Paraguay, where according to his blog he spent four weeks taking Spanish lessons.
On 28 April, he entered the Defensores del Chaco national park, signing the necessary permit. Reportedly he had plans to travel on to Bolivia after exploring Cerro León.
Officials analysing calls made from Mr Wabnegg's satellite and mobile phones said the last signal they picked up was from 2 May.
His friends back home reported him missing after he failed to make it to Bolivia.
Police said his motorhome was intact, with no signs of a break-in or breakdown.