Ten plantation companies operating in Riau, South Sumatra, Jambi and Kalimantan provinces may see their licences revoked, and may be fined as investigators probe whether they engaged in intentional burning to clear land ahead of the planting season later this year.
Preliminary evidence shows that the companies, which have either oil palm or wood pulp concessions, contributed to the raging fires that spread uncontrollably in the past weeks, spawning thick haze that has sent air pollution indexes in Singapore and Malaysia to between moderate and unhealthy levels.
"Investigations are ongoing. We will immediately announce the names of the companies once we group them into three classes - mild, moderate and heavy breaches," Environment and Forestry Ministry spokesman Eka Soegiri told The Straits Times by phone.
Under Indonesian plantation law, a company found guilty of clearing land by burning can be fined up to 10 billion rupiah (S$1 million), and the management faces up to 10 years in jail.
Companies that fail to control fires started elsewhere but which spread into their concession land also face punishment. The law requires them to have adequate equipment and personnel to control fires within their land.
"In each of the 10 cases, investigators are studying what caused the fire, how it spread, the impact of the fire, how much effort the plantation company put in to control the fire, and the economic losses the fire caused," Dr Eka said.
One of the 10 companies has been identified as PT Tempirai Palm Resources in South Sumatra province, where 45ha of its concession land caught fire.
Mr Ali Hanafiah, Tempirai's manager in charge of emergency response, blamed local farmers who started a fire nearby that spread into his company's concession land owing to strong wind, Kompas daily reported yesterday.
Meanwhile, in Jambi, police have named 20 farmers in their investigation of eight cases of forest and land fires since January, reported The Jakarta Post.
Haze from forest and land fires deteriorated in Kalimantan and lingered in Sumatra yesterday as officials - in some places facing a lack of equipment - struggled to douse the raging fires.
The thick haze has disrupted flights in Riau, Jambi, South Sumatra and Kalimantan, and forced schools to close temporarily.
There were 616 hot spots detected yesterday in West Kalimantan alone, reported Kompas. But light rain provided some respite in Riau, increasing visibility in the capital as well as the northern parts of the province, according to Antara news agency.
Mr Syaikhul Islam Ali, an MP in the environment committee, blamed weak law enforcement for the recurring problem of forest fires. "Destroying forests, whether on a small or big scale, is a serious crime. The environment minister should not be reluctant. Whoever the culprits are, give them stern punishment."