There are currently an estimated 5,000 to 7,000 Sumatra orangutans left. The International Union for Conservation of Nature lists them among the "World's 25 Most Endangered Primates”. The main reason is deforestation to make way for agriculture and illegal logging. PT Kallista Alam is thought to have deliberately and systematically broken Indonesian law to convert parts of the Tripa forest into a palm oil plantation. This was discovered as part of an investigation conducted by the environmental protection authorities as part of a billion-dollar deal with Norway to preserve the Indonesian forests. Some 200 orangutans in the Tripa forest are currently at risk.