Environmental campaigners WWF on Thursday condemned moves by British firm Soco International to start searching for oil in part of Africa's oldest national park.

WWF said that Soco was on Saturday scheduled to start seismic testing in the Democratic Republic of Congo's Virunga park, home to 3,000 species including the endangered gorillas immortalised by the film "Gorillas in the Mist".

"WWF condemns in the strongest terms Soco's unacceptable operations in Virunga National Park," said Lasse Gustavsson, head of conservation at WWF.

"It is irresponsible for Soco to disregard the national and international laws protecting this World Heritage Site. The company is putting the livelihoods of thousands of people at risk," he said in a statement.

WWF said people living near the park had warned that parts of Lake Edward -- a huge expanse of water that is partly within Virunga's boundaries -- were set to be closed to fishing while Soco searched for subterranean oil reserves.

Lake Edward's fishery generates an estimated $30 million (21.7 million euros) annually for residents living near the park, WWF said.

WWF said Soco's own environmental impact assessment had indicated that exploratory drilling could lead to air pollution, lung diseases, water contamination, invasive species or habitat loss in the fragile ecosystem.

Soco has rejected the criticism, saying it understands Virunga's importance and takes the issue seriously, with plans to work in partnership with locals to help conserve the park while also ensuring economic development. It has also ruled out drilling at present.

"SOCO is a responsible company and is extremely sensitive to the environmental significance of the Virunga National Park," the firm said on its website.

"SOCO's only planned activity continues to be the scientific studies involving environmental baseline studies, social investment projects and a seismic survey of Lake Edward due to start shortly," the statement added. "No drilling has been planned or is warranted at this stage."

WWF said the oil industry had no place in the park.

"Virunga could be a source of hope for eastern DRC if its fisheries, hydropower and ecotourism potential (are) developed sustainably. Soco should not be allowed to threaten the future of this irreplaceable park," said Gustavsson.

He urged Soco's shareholders to reject oil exploration in Virunga.

The 7,800-square-kilometre (3,000-square-mile) Virunga park was created in 1925 when the country was a Belgian colony.

Despite its own environmental rules and international accords, the government of conflict-wracked but resource-rich DR Congo in 2007 awarded oil concessions in much of the park.

The UN cultural body UNESCO has said oil exploration and exploitation would breach Virunga's World Heritage site status, and in May last year French giant Total -- Soco's fellow concession holder -- said it would not drill there.