"The destruction of high biodiversity forest in Sumatra's Bukit Tigapuluh landscape -- including the extinction of the endangered Sumatran tiger, elephant, and orangutan -- is now in front of our eyes," five environmental groups, including the World Wildlife Fund, said in a joint press release.

The groups said the flora and fauna, including the rafflesia, the world's biggest flower, are also threatened by a Forestry Ministry plan to revive the expired logging concession in Bukit Tigapuluh national park and give it to APP and its partners.

Bukit Tigapuluh or "The Thirty Hills" occupies 130,000 hectares (320,000 acres) of tropical rainforest in Jambi province in southern Sumatra and represents one of the most biologically diverse habitats on earth, with 59 mammal species and 198 bird species.

Natural forests in Jambi have become a new target for companies supplying wood to pulp and paper companies including to APP, because their activities in neighbouring Riau province have been stopped due to a police investigation of illegal logging there, the report said.

Green groups have frequently accused APP of destroying natural forest in Indonesia. In March 2007, Greenpeace accused it of illegal logging in protected forests in Southern China.

According to Greenpeace, Indonesia had the fastest pace of deforestation in the world between 2000 and 2005, with an area of forest equivalent to 300 soccer pitches destroyed every hour.

APP and its partners are clearing areas where forest concessions have expired and building logging roads.

PT Arara Abadi and PT Wirakarya Sakti, which supply fibre to APP, have cleared about 20,000 hectares of natural forest in Bukit Tigapuluh and supplied the wood to APP subsidiaries in Riau and in Jambi, the report said.

"With its high conservation values, Bukit Tigapuluh should be protected and therefore all natural forest clearance in the area has to be stopped," said Ian Kosasih, forest programme director of the World Wildlife Fund in Indonesia.

APP is one of the world's leading pulp and paper companies with combined pulp, paper and packaging capacity in Indonesia of more than 7 million tonnes, according to its Web site.

The report was produced by Indonesian green group WARSI, Sumatran Tiger Conservation Program, Frankfurt Zoological Society, the Zoological Society of London, and WWF-Indonesia following investigations in September and November last year.

The group also found PT Wirakarya was building a new logging highway through natural forest, splitting the national park into two.

APP said that it had received a permit to build the road access and that it had been in talks with local green groups and local government on expanding the national park's boundaries.

"The licence for the development of the access road referred to has been granted by the relevant authorities," Aida Greenbury, APP's vice director of sustainability and stakeholder engagement, said in an e-mailed statement.

She said that APP made sure that no illegal wood was used in its internal supply chain.