Nabiel Makarim said the road network, ostensibly aimed at linking isolated communities in the west of Aceh province, could worsen illegal logging and lead to forest destruction.

"This will give access to illegal logging, which we are still unable to deal with," Makarim told a seminar.

"If illegal logging happens the forest will be destroyed. If that happens -- let's not talk about monkeys first but human beings -- that area will become withered during the dry season and suffer flooding during the rainy season."

He said alternative routes to avoid the conservation area -- an area almost the size of Belgium -- have been proposed.

Environmentalists say the roads would threaten wildlife and damage the water supply from the area known as the Leuser Ecosystem, which is home to Sumatran rhinos, orangutans, tigers and elephants.

European Union Environment Commissioner Margot Wallstrom last month visited the EU-funded conservation project and expressed alarm that the roads could spell disaster for the zone covering 2.6 million hectares (6.4 million acres).

The EU has spent 31 million euros (37.2 million dollars) on the conservation area since 1996, parts of which are a national park. The Indonesian government has contributed six million euros.

Work has already started on the network.

Megawati on Sunday called for the project to go ahead, saying only a small part of it was considered to threaten the environment.

A team of concerned ministers would visit the area and review the parts that touched the conservation area, Megawati said.

Makarim said he would meet the president to clarify her position on the matter.

Environmental activists have filed a complaint with police in Jakarta against Infrastructure Minister Sunarno and the governor of Aceh province Abdullah Puteh, who support the project.

TERRA.WIRE