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(CNN) He has been beaten, threatened and imprisoned. But the former child soldier and winner of this year's Goldman Environmental Prize says he will not stop until those wanting to destroy the Democratic Republic of Congo's protected wildlife "are held responsible for their actions."

"Even if I or others are not able to (make this happen)," says Rodrigue Mugaruka Katembo, "then the future generations will have this information and will do it."

Katembo who is 41, has been awarded the top environmental prize in recognition of the heroism he showed in preventing oil exploration inside Virunga -- Africa's oldest national park. His dangerous undercover investigations exposed bribery and corruption among officials.

Conservationists say oil exploration would have threatened the habitat of the park's critically endangered gorillas, elephants and lions.

Saving gorillas, a dangerous job

The park is home to a quarter of the world's last remaining mountain gorillas, there are less than 900 left globally. Covering the size of a small country, Virunga is more than 3,000 square miles packed with volcanoes, lush forests and mountain glaciers that tear through the Democratic Republic of Congo, Uganda and Rwanda.

As a park ranger, Katembo has one of the most dangerous jobs in the region. Amidst political instability, armed poachers and rebels -- who have been warring in the park for the past 20 years -- outnumber park rangers ten to one.

"Some of them were illegally arrested, others paid the ultimate price for the protection of Virunga," says Katembo. "They really fought with their heart to protect the park."

Photos: Protecting Africa's oldest park



Today, as a ranger he risks his life to protect Congo's critically endangered species. He's one of six recipients of this year's prestigious



Pictured: Katembo during an anti-poaching operation in Virunga National Park. Rodrigue Mugaruka Katembo was forced to be a child soldier in the armed conflict that has engulfed the Democratic Republic of Congo for the past few decades.Today, as a ranger he risks his life to protect Congo's critically endangered species. He's one of six recipients of this year's prestigious Goldman Environmental Prize Pictured: Katembo during an anti-poaching operation in Virunga National Park. Hide Caption 1 of 12 Photos: Protecting Africa's oldest park



Pictured here, a male elephant bathes and drinks water on the Northern shores of Lake Edward inside Virunga National Park. The park continues to dramatically lose its elephant population due to poaching. As a park ranger at Virunga -- Africa's oldest national park -- Katembo has one of the deadliest jobs. The park is a backdrop to one of the world's longest running wars, more than 160 of its rangers have been killed in the last two decades mainly by poachers and armed militias.Pictured here, a male elephant bathes and drinks water on the Northern shores of Lake Edward inside Virunga National Park. The park continues to dramatically lose its elephant population due to poaching. Hide Caption 2 of 12 Photos: Protecting Africa's oldest park Katembo's award is for the courage he showed in so far preventing oil exploration inside Virunga.



The park is home to a quarter of the world's last remaining mountain gorillas. The size of a small country, Virunga covers more than 3,000 square miles rich with volcanoes, lush forests and mountain glaciers that tear through the Democratic Republic of Congo, Uganda and Rwanda.

Hide Caption 3 of 12 Photos: Protecting Africa's oldest park Virunga can also claim the world's largest lava lake, a roiling 250-meter wide cauldron of steam and smoke. Hide Caption 4 of 12 Photos: Protecting Africa's oldest park



The lake is at the heart of Virunga's ecosystem, and it's estimated that two hundred thousand local people depend on it for food and work.



Pictured, a Congolese woman arranges fish into clusters to sell at her stand in the southeastern Kivu province. Conservationists say oil drilling in the park would have threatened the habitats of the park's critically endangered animals including elephants and lions. Environmental watchdog Global Witness feared it would have choked Lake Edward, inside Virunga's boundaries and the smallest of Africa's great lakes.The lake is at the heart of Virunga's ecosystem, and it's estimated that two hundred thousand local people depend on it for food and work.Pictured, a Congolese woman arranges fish into clusters to sell at her stand in the southeastern Kivu province. Hide Caption 5 of 12 Photos: Protecting Africa's oldest park Pictured here, rangers destroy an illegal charcoal kiln while conducting an anti-charcoal patrol in the Kibati region of Virunga National Park, in 2008.



There were eight active charcoal kilns in an area where the forest had been cut to the ground and trees burnt for charcoal production. Hide Caption 6 of 12 Photos: Protecting Africa's oldest park "The park brings a lot of different kinds of services that are benefiting the community," Katembo told CNN.



"For instance you have the protected fisheries where many fishermen are able to sustain their families and are able to have income generation."



Pictured, a ranger looks out over Virunga. Hide Caption 7 of 12 Photos: Protecting Africa's oldest park In 2013, Katembo was arrested and held for 17 days. He believes it was because days prior to his arrest he had attempted to stop construction of a communication device in the park. Public outrage led to his release.



Pictured here, Katembo meets with a group of widows whose husbands are among the park rangers killed in the line of duty, often at the hands of armed rebels and poachers. Hide Caption 8 of 12 Photos: Protecting Africa's oldest park Katembo has loved wildlife since he was young. "All national parks are a reservoir of biodiversity in DRC, to lose the park will be to lose all the biodiversity of the area, impacting on the future of the next generations, " he tells CNN. "When protecting the park we also contribute to the fight against climate change," he adds.

Pictured here, a ranger protects an area of the forest in Virunga National Park where trees have been cut for illegal charcoal production. Hide Caption 9 of 12 Photos: Protecting Africa's oldest park Pictured here, the son of a Congolese park ranger, who had been working in the Virunga National Park, is lifted onto a truck, in November, 2008, as families leave a camp for Internally Displaced People (IDP) in the North Kivu provincial capital of Goma.

Park rangers and their families were relocated to a larger IDP camp during violent clashes amongst different militias. Its rangers are not immune to the conflict that has mired the country, and continue to pay the ultimate price for conservation. Hide Caption 10 of 12 Photos: Protecting Africa's oldest park Now as director of DR Congo's Upemba National Park, Katembo faces many of the same challenges he battled at Virunga. Here gold and emerald mining as well as armed poachers pose the biggest threat to the park's biodiversity.



"We need to have the same kind of strategies in place to combat illegal mining exploration in the park and have the laws be respected like we did in Virunga," he says. "We need to have a support at national and international level. Hide Caption 11 of 12 Photos: Protecting Africa's oldest park He hopes to be able to develop ecological activities around the park's boundaries that will provide income for its local community. But due to lack of finance, there is only one truck to patrol over 4,000 square miles.



Pictured, Rodrigue Katembo. Hide Caption 12 of 12

Katembo has loved wildlife since he was young. But like many in the African nation, he has been touched by war. When he was 14 years old in 1989, Katembo was taken as a child soldier, during the Democratic Republic of Congo's long running armed conflict.

He would remain a soldier for eight years in different rebel groups. After peace was briefly restored, he began work at Virunga, in 2003, protecting the land and healing the community.

"The park brings a lot of different kinds of services that are benefiting the community," he told CNN. "For instance you have the protected fisheries where many fishermen are able to sustain their families and are able to generate income."

A man stands on the back of a truck in Rumangabo. Virunga is a picturesque backdrop to one of the most violent and longest runing armed conflict.

'You deserve to die', threats and shootings

Protecting Virunga hasn't been easy.

In 2013, Katembo was arrested and held for 17 days. He believes it was because days prior to his arrest he had attempted to stop construction of an oil communication device within the park.

Katembo says he received phone calls telling him: "You have betrayed the country ... You deserve to die."

Local chiefs have offered him bribes, "to help them get oil exploration going in the park," he says, "they proposed $5,000 just to do that." This figure would have been nearly five times his annual salary.

Netflix documentary highlights struggle

Photos: Virunga's gorilla rangers risk armed rebels and poachers Virunga, the crown jewel of Congo's eco-tourism trade, is an area of extraordinary biodiversity and an important habitat for mountain gorillas. Bukima (pictured here) is a silverback, adopted by his current troop after poachers killed four gorillas including the dominate male. Hide Caption 1 of 8 Photos: Virunga's gorilla rangers risk armed rebels and poachers Mountain gorillas share 98% of their DNA with humans but are critically endangered, due to shrinking habitats and poaching. There are less than 900 left in the world, in only three countries: DR Congo, Rwanda, and Uganda. Around a quarter live inside Virunga.



"To get a baby gorilla you need to kill the whole family. The habitat is very reduced and put lots of pressure on the gorillas, so we need to do all that we can to protect them," says Rodrigue Katembo, director at Upemba National Park in southeastern Democratic Republic of Congo and 2017's Goldman Environmental Prize winner. Hide Caption 2 of 8 Photos: Virunga's gorilla rangers risk armed rebels and poachers "The gorillas are also part of the culture of the local communities in the Virunga mountains, and they are an important source of revenue for the economies of the countries profiting from gorilla tourism," he adds.

During their patrols, rangers invariably come into contact with armed poachers or groups of armed people staying in the forest. Gorilla habitats in the park have often been occupied by rebel movements. Despite this, the gorillas continue to survive, largely due to the park rangers' efforts

Hide Caption 3 of 8 Photos: Virunga's gorilla rangers risk armed rebels and poachers In 2007, four gorillas were targeted, executed at point blank range inside Virunga. One of the three female gorillas killed was pregnant. Their lifeless bodies, including the troop's magnificent 500-pound silverback, were strapped to bamboo poles and carried down the mountain to be buried. Hide Caption 4 of 8 Photos: Virunga's gorilla rangers risk armed rebels and poachers A park ranger, working in the Virunga National Park, smiles at his 9-month-old daughter after he, and other park ranger families, came back to their homes in Rumangabo in 2008. The rangers and their families had to flee their homes after heavy clashes between armed groups broke out in and around the park. Hide Caption 5 of 8 Photos: Virunga's gorilla rangers risk armed rebels and poachers A Virunga National Park ranger stands at an observation post at Rumangabo, east at the edge of the park. Hide Caption 6 of 8 Photos: Virunga's gorilla rangers risk armed rebels and poachers A park ranger uses a camcorder to film an adult gorilla while conducting a gorilla population census, on the slopes of Mount Mikeno. There are 220 documented gorillas living in Virunga. A new census count on gorilla numbers within the park is due to begin this year. Hide Caption 7 of 8 Photos: Virunga's gorilla rangers risk armed rebels and poachers Conservationists hope Virunga's ambitious $200 million clean energy project will help provide economic development of the region. The Matebe hydroelectric plant will bring sustainable energy to the region for the first time when operational. It is one of eight plants being built in the area. All are set to be online by 2025, generating enough electricity to power the entire North Kivu region.

Here, workers weld pipes that carry water from the mountains of Virunga down an embankment and into a turbine hall that sits above an expansive savannah below. Hide Caption 8 of 8

The documentary follows Katembo, colleagues André Bauma, Emmanuel du Merode and French investigative journalist Mélanie Gouby, as they battle oil exploration and armed conflict in the park.

In 2010, UK oil giant SOCO was authorized by the DRC government to explore for oil within parts of the park.

Conservationists said the move was illegal because of the park's status as a UNESCO World Heritage site . There were allegations of intimidation of local communities and rangers including Katembo. SOCO has denied the claims and in 2014 ended its project

Zebra numbers are on the rise at Upemba National Park, thanks to Katembo and his local rangers.

Following the film and Katembo's investigations, campaigns by the World Wildlife Fund (WWF) have so far kept oil exploration out of Virunga.

New chapter

In 2015, Katembo became director of Upemba National Park, in southern DRC. Here, he faces many of the challenges he battled at Virunga. Gold and emerald mining as well as armed poachers pose the biggest threat to the park's biodiversity. Armed rebel groups control parts of the park.

For their safety, he lives apart from his family and small children, seeing them just every six months.

"We need to have the same kind of strategies in place to combat illegal mining exploration in the park and have the laws be respected like we did in Virunga," he says.

"We need to have a support at national and international level."