An Australian man who remains missing in Nepal nine days after a catastrophic earthquake rocked the Himalayan nation was seen trekking into an area that is now known to have been partially obliterated by a quake-triggered landslide.

The family of Tyronne White are desperately clinging to the hope that the 44-year-old, originally from Taree on the NSW Mid North Coast, is stranded in a remote area near the Langtang Track and cannot get word back to his family that he survived.

But Mr White's cousin Marc Wade Patek said that, as the days passed, his family were facing the harsh reality that he may not have survived the natural disaster, which is known to have killed at least 7200 people.

Mr Patek said a fellow traveller bumped into Mr White in the village of Langtang, north of Kathmandu, on April 23, two days before the earthquake struck.

The pair had lunch, and Mr White told the other traveller, who was heading in the opposite direction, that he was planning to hike further up into the mountains on his own.

At the weekend, police officer Prabin Pokharel told AFP that a rescue operation in Kenjing Valley, along the Langtang trekking route, found the bodies of 48 people, including at least three foreigners, buried under a landslide.

More than 200 people, about half of them foreigners, were still believed to be buried there, he said.

Mr Patek said he knew his cousin would be trying to get in touch with his family in Australia if he had survived.

He said Mr White was physically fit and had travelled the world for years on his own, sometimes returning to Australia for periods to save money for his next adventure.

"I still believe, if he's stuck in a village, he would be happy to stay and help them, but he would at least get a bit of paper to a helicopter and ask them pass it on to the family," Mr Patek said.

"It's such a vast area, there are places they haven't even got to yet. God knows how high up he got.

"It's been so long [since the earthquake], we are on edge, not wanting to believe anything bad has still happened.

"His father can hardly talk, his mum is just pretending everything is going to be OK, thinking he will pop up somewhere."

Mr Patek said he and his family had been dismayed by Foreign Affairs Minister Julie Bishop's comments last week that virtually all 1450 Australians known to have been in Nepal had been accounted for.

"Instantly, everybody was ringing up and saying, 'Wow, congratulations, that's such good news,' " Mr Patek said.

"Suddenly you have to go into this zone again to let everyone know he's still missing. It literally doubled instantly our stress levels."

Mr Patek urged any Australians who had returned from Nepal and who had encountered Mr White in their travels, or who had any information about him, to contact authorities.

A Department of Foreign Affairs and Trade spokeswoman said on Monday: "There are 1465 Australians, including permanent residents, in Nepal that have now been accounted for. It was believed that virtually every Australian had been accounted for, but we have recently become aware of further information indicating that not all Australians affected by the earthquake have been contacted or located. We are concerned about Australians who may have been in the Langtang area and have deployed two Australian government officials to urgently confirm the welfare of Australians in this region."