The population of Orangutans in Kalimantan or Borneo Island of Indonesia remained under threat of extinction, despite claims by palm oil firms of applying eco-friendly work practices, according to a newspaper here Saturday.

Deforestation for palm oil plantation was blamed for the killing the protected apes, particularly those living outside conservation areas, said Novi Hardianto, the habitat program manager of the Center for Orangutan Protection (COP).

"The forest is continuously being cleared and orangutans are killed every year. It's ironic," he was quoted by the Jakarta Postas saying.

The manager said a recent investigation by the group show that two palm oil firms in Central Kalimantan, both of them members of the Roundtable on Sustainable Palm Oil (RSPO), endangered orangutan populations with their clear-cutting.

RSPO spokeswoman Desi Kusmadewi denied the accusation, saying the RSPO sought to improve environmental practices within the palmoil industry.

The province is home to the country's largest orangutan population. In 2004, there were 31,300 orangutans but the figure was declining by 9 percent each year, with the current population at 20,032, the COP estimated. 　

Source: Xinhua