An uncontacted Amazon tribe could be at risk as Brazil makes austerity-driven budget cuts and proposals for constitutional change affecting land rights move through parliament, campaigners have said.

The tribe were photographed from a helicopter by Ricardo Stuckert this month near the border with Peru.

“These are dark times if you’re an indigenous person in Brazil,” said Fiona Watson, a field director at the London-based human rights organisation Survival International. “For the people in those photos the biggest threat is the loggers and drug traffickers on the Peru side. That’s the immediate, visceral threat. But the other threat is thousands of miles away in [Brazil’s] congress.”

The prospect of budget cuts to the governmental body tasked with protecting indigenous people, Funai, could be the “writing on the wall” for the tribe and the 102 other such uncontacted groups in Brazil, Watson said.

The UN special rapporteur for indigenous rights said this week that federal funding for the department had all but dried up, leaving staff overworked and dealing with a backlog of cases.

Indigenous rights groups are also concerned by PEC 215, a proposed constitutional amendment working its ways through congress that campaigners say could threaten the land rights of indigenous people.

But Watson, who has lived in the Amazon rainforest and has met members of previously uncontacted peoples, said she believed the tribe could still thrive. The people live in a very remote part of the rainforest and the Acre state government is relatively sympathetic to indigenous people’s rights.

Stuckert and José Carlos Meirelles, a tribes expert with the Acre government, who was also on the helicopter, reported that the estimated 300 members of the tribe appeared healthy.

While Watson admitted that little was known about the tribe, the photographs showed a substantial and well-made house, gardens and crops.

The bows and arrows carried mean the tribe almost certainly hunts for meat. “I imagine hunting is pretty good in that area – tapir, capybaras, wild pigs, probably deer, monkey. They probably do some fishing as well, they probably eat shellfish and crabs.” The tribe is likely to be semi-nomadic, said Watson.

The uncontacted tribe. Photograph: Ricardo Stuckert

The people fired arrows at the helicopter. “They’re messages. Those arrows mean ‘leave us in peace, do not disturb’,” Meirelles told National Geographic.

“I think it’s clear that they want to remain uncontacted,” said Watson. “One can speculate that they are the descendants of the people who escaped the rubber boom in that area 100 years ago, and have an awareness of the outside world.”

In some cases, uncontacted groups have been driven into making contact owing to other pressures. In 2014, previously uncontacted tribesmen were filmed after they crossed into Brazil from Peru and told people they had been driven out of their forest home by people presumed to be drug traffickers.

The situation is reportedly worse for tribes over the border in Peru, where Survival International estimated there are 15-20 uncontacted groups. “We know there is a huge amount of illegal logging and drug trafficking, and it’s pretty much out of control in Peru,” said Watson.

Brazil’s policy is to leave tribes alone unless they approach the outside world. But before 1987, the policy was to contact such people, in what Watson called a “paternalistic, we know best” attitude, rather than leaving them to self-determination.

The results, as people were exposed to viruses such as flu for the first time, were often catastrophic. “There were disastrous contacts where well over 90% of a tribe died within a month of coming into contact: the Panará people, the Matis people, the Awá people,” said Watson.

In July this year, the Brazilian government rejected calls from two US anthropologists to rethink its policy of contact.