Minas Gerais, Brazil - "Do not speak of Samarco. The word is cursed, just as the river is cursed."

The warning came from an agent of Brazil's National Indian Foundation (FUNAI) which oversees the country's indigenous people, including the villages of the Krenak tribe who live on the banks of the Rio Doce, which runs through the mining heartland of Minas Gerais.

The FUNAI agent was referring to the mining company Samarco, a joint venture between Brazil's mining giant Vale and Anglo-Australian BHP Billiton.

On November 5, 2015, a sea of toxic mud and mineral waste flooded out of the Fundao dams operated by Samarco, killing 19 people, destroying homes and polluting waterways.

Since the flood, which is widely regarded as Brazil's worst ever environmental disaster, life on the riverbank has been completely transformed.

READ MORE: Brazil's Fundao dam collapse - The silence after the mud

Before the disaster, the 126 indigenous families who lived in the seven villages would hunt fish, capybaras, armadillos and other animals, and use the Rio Doce for drinking water and to irrigate their crops. Now they eat beef, chicken and pork bought at nearby supermarkets.

After the mud arrived, Samarco prohibited the tribe from fishing and installed a fence to keep the tribespeople from approaching the sacred waters of the "Watu", as the Rio Doce in known in the Krenak language. Following complaints, the fence was removed. The children now bathe in a water tank installed by Samarco.

The death of the Watu has caused the Krenak to lose their identity.

The arrival of the mud has disrupted the tribe's ability to produce handicrafts, a big source of income. The oba, a seed found on the banks of the Rio Doce, was also contaminated.

"We live to hunt and to fish and now we cannot," says Dejanira Krenak, 67, one of the village elders.

"The river has many fish; our native diet is fish. But for us, the river died."

READ MORE: Kenya's Ogiek win land case against government

WATCH the full documentary here: Brazil's River of Mud (25:00)

'Our culture is dying'

Leonir Boka, who is 31, has been the chief of Atora village since he was 23 years old. He never imagined that the 25 families from his village would face such destruction.

"We have no home, no money or any means to pay for what they did to the river, what they did to us," he says. "If we could choose anything in this world, we would want the river back."

No one goes near the river. Baptisms and sacred rituals performed on its banks and its small islands have ceased. Cases of depression, alcoholism and diseases have multiplied as the time passes, according to the tribe's chiefs and FUNAI.

The last time I was hospitalised for nine days after I entered the water to get my boat off the sand. I vomited non-stop, and my intestine was weak. Jose Krenak

"The river was a strong medium where we practised our culture, and today, we cannot do that anymore," Boka says.

"Our elders would perform sacred rituals on the islands of the Watu. Just as the Rio Doce died, our culture is dying."

Samarco is taking steps to compensate victims of the disaster, including making payments of indemnities to those affected. It launched the Renova Foundation in 2016, which manages the payments.

Renova does not reveal the sum paid for each family, but the villagers have said they receive 7,000 Brazilian reals ($2,254) a month, which is higher than what is paid to other victims of the disaster, such as fishermen. The villagers are still receiving payments.

"This transfer of funds is part of an emergency agreement that was reached in negotiation with indigenous leaders, mediated and monitored by FUNAI," Renova said in a statement to Agencia Publica.

The injection of money by Samarco enabled the tribe to build new houses, replacing small shacks of straw with homes made of wood or bricks. The garages boast new cars and motorcycles - a Chevrolet, a Toyota, a Volkswagen - and many families also have cable television and state-of-the-art mobile phones.

'It was a sweet river'

The biggest problem, however, is for those who come into direct contact with the Watu's water.

Jose Krenak, 66, transports residents across the Rio Doce daily in his boat. Unable to avoid the water, he says he has contracted various skin diseases.

"The last time I was hospitalised for nine days after I entered the water to get my boat off the sand. I vomited non-stop, and my intestine was weak," he says.

"I try not to touch the water because it irritates the whole body. When I have to touch it, I put on my trousers. But there is no way. It is poisoned water."

He smiles and offers a boat trip through the orange-brown waters.

"It was the sweet river, but it's bitter now," he says.

READ MORE: Seeking answers to catastrophic Brazil mine disaster

One of the village's oldest residents, Euclides Krenak, died of natural causes in December when he was 107 years old.

His brother, Dejanira Krenak, recalls what it was like for Euclides to witness the disaster.

"It was disgusting for him to see the river in such a state. I said, 'Do not feel like that. Ask God for strength, only Tupa can help us,'" he says. "But he expired with so much sorrow."

Samarco has also supplied 100 drinking fountains, silage and feed for cattle and boats. It has also provided healthcare support.

Rather than remove the toxic mud, Samarco is focusing on directing more water from tributaries to slowly decontaminate the Rio Doce.

The company, contacted through Renova, was not able to predict when the Krenak will be able to use the river again. Of the 101 tributaries in the Rio Doce basin, 56 have been restored and another 32 are being considered for a restoration programme, a Renova spokesman said.

In all, the Renova Foundation has said it is working to recover 5,000 tributary sources across the region, which is slightly smaller than France, over the next 10 years. This work should improve the conditions of the Rio Doce, but some warn it alone will not be enough for the Watu to come back to life.

'Everything will be destroyed'

A few decades ago, dozens of streams and springs led into the River Doce here, but now nearly all have run dry due to the building of dams or the pumping of water to farms.

In the last 10 years, the villages lost 64 sources of water. Now, only three remain.

The Krenak tribe want to return to another part of their sacred lands called Sete Saloes, on the other side of the Rio Doce, which still has many springs.

But the Sete Saloes is occupied by landowners, whom the tribe claims have built luxury mansions on the land and who will not allow the tribe to have access.

Since 2015, federal prosecutors have sought to demarcate the land of the Sete Saloes for the tribe. This would give the Krenak tribe the right to live there, the same rights as it was granted in other parts of its homeland in 1997.

"Many of our relatives have died fighting for this land, to regain our territory," says Lily Krenak, 54, referring to the demarcation in 1997.

"If we do not take care, the same thing will happen there as happened to the river. Everything will be destroyed, everything will be ended."

Prosecutors are also demanding further environmental compensation for the dam collapse and moral damages for the Krenak people.

"There are damages from various perspectives, including the spiritual [perspective]," prosecutor Edmundo Antonio Dias Netto Junior says. "They are unable to perform their sacred rituals on the banks."

In truth, the fight of the Krenak people is only just beginning.

This report was produced by Agencia Publica, a non-profit investigative journalism agency based in Brazil. This is a translation of the original version, published in Portuguese here.