Temasek Holdings said it fully supports "no burn" policies for land clearance, and urged oil palm companies and plantation owners to do the same.

The statement released on Monday came as commodity trader Olam International, majority-owned by Temasek, defended itself from allegations that it was causing deforestation in Gabon, central Africa.

Temasek said it does not direct business operations of its portfolio companies, but stressed that all players involved should work together to prevent and minimise risks to people and the environment.

"We have stated openly and in many forums, that we fully support no-burn policies for land clearance, and would urge oil palm companies and plantation owners to do the same," Temasek said, adding that haze from large-scale fires is a major health hazard.

Singapore-listed Olam was accused by non-governmental organisations of clearing about 20,000ha of forest across its four legal concessions since 2012, roughly a third the size of Singapore.

Singapore regularly suffers from haze caused by slash-and-burn practices by small-scale farmers and rogue palm oil traders in neighbouring Indonesia, who cause agriculture fires to clear vegetation for palm oil, pulp and paper plantations.

"It is important that all players, individuals, companies and governments, work together to prevent, minimize and mitigate such risks to people and our environment," the Temasek statement added.