His body was found in scrub this afternoon about 1km from his car, which was discovered on Friday abandoned about 10km south of Glendambo, almost 600km northwest of Adelaide.
South Australian police say the body is believed to be that of Mr Richards, although that will not be confirmed until a post-mortem examination has been carried out.
"While investigations will be continuing, there appears to be no suspicious circumstances at this time," a police statement said.
Detective Inspector Denise Gray said it appeared Mr Richards walked off after his car was damaged in the rough terrain.
"It appears that the vehicle had been driven to that location over rough terrain and the vehicle sustained front-end damage and a shredded left front tyre and was most likely undriveable," Det Insp Gray told reporters in Adelaide, before police found the body.
She said there were no signs of violence in the car.
"It appears that he's become disorientated and the vehicle's not working, so he's decided to walk," she said.
Mr Richards went missing while driving from Darwin to Ballarat.
Earlier this month, police described the search as looking for a needle in a haystack after covering 4300sq km by air and land without any sign of the man or his car.
His dog was found alive near Glendambo on July 10, but the search was called off on July 19.
Mr Richards was carrying enough fuel to travel about 4000km and a quantity of food when he left Darwin to drive to Ballarat last month.
The father of two last contacted his partner on Monday, June 20, from Coober Pedy to say he would arrive home the following day.
Relatives missed another call from him on the Tuesday morning, which came from the Woomera region.
The last confirmed sighting was on the morning of June 21 on the Stuart Highway, about 10km south of Pimba, in South Australia's north.
The 28-year-old flashed his car lights at a truck driver to get him to stop and had a brief, but incoherent, conversation with him.