Jakarta – Indonesia's illegal logging industry is backed by high-level corruption, an international environmental group charged here on Wednesday, as the World Bank said the country's commercial forests could be exhausted within 10-15 years.

"The government has to deal with the corruption and collusion that is behind the [illegal] logging" in national parks, Mr Dave Currey of the Environmental Investigation Agency (EIA) told reporters after addressing a World Bank-sponsored forestry seminar.

The British and US-based non-governmental organisation made its allegation after presenting a report on illegal logging at the Tanjung Puting national forest, Central Kalimantan, to a group of Indonesia's major aid donors.

Faith Doherty of the EIA, and Ambrosius Ruwindrijarto of its Indonesian partner Telapak, said they were attacked on Saturday by workers at a sawmill in Pangkalan Bun town at the entrance of the forest about 900km north-east of Jakarta.

The pair were detained by local police for several hours, but later "rescued" by the Indonesian military and other environmentalists.

The mill, PT Tanjung Lingga, is owned by Indonesian MP Abdul Rasyid and sits at the entrance of the reserve, a diminishing tropical rain forest filled with rare animal and plant species, including many of the country's s protected orangutans.

The World Bank estimates Indonesia's tropical rain forests are disappearing by some 1.5 million hectares a year.

At the Consultative Group on Indonesia (CGI) meeting, the World Bank delivered a paper saying that Indonesia's commercial forests could be exhausted in less than two decades if rampant illegal logging and clearing, weak law enforcement and other poor industry practices were not stopped.

"It is feared that, at the present rate, the commercially valuable forest resources will be exhausted within 10 to 15 years," said the paper, which was distributed at a World Bank- sponsored conference.