The USA has launched an anti-dumping investigation into Indonesian and Argentinian biodiesel imports after the National Biodiesel Board (NBB) filed a complaint with the US Department of Commerce in March, according to the NBB.

The International Trade Commission (ITC), part of the commerce department, was expected to make a preliminary decision on 5 May on whether or not the biodiesel import hurt domestic producers, the NBB said on 13 April.

In testimony to the ITC given on the same day, the NBB said biodiesel imports from Argentina and Indonesia had surged by 464% from 2014 to 2016, taking 18.3% of market share from US manufacturers.

“2016 should have been a banner year for US biodiesel producers with demand growth, stable feedstock prices, and regulatory certainty that should have led to profitability and reinvestment in their businesses, but unfortunately that didn’t happen,” said NBB vice president of federal affairs Anne Steckel. “Instead, dumped and subsidized biodiesel from Argentina and Indonesia entered the United States in record volumes.”

Oke Nurwan, director general for foreign trade in Indonesia, told Reuters that the Indonesian government would be cooperative in the investigation by providing arguments and supporting data showing there had been no dumping or subsidies.

Argentinian biodiesel producers were claiming that the USA would now have to prove that dumping and illegal subsidies were taking place.

“Now they have to prove everything that they’re claiming, which is a sham. It’s a protectionist measure. We hope that the US offers a fair process, which will show that there is no dumping or subsidies of Argentine biodiesel,” said Argentina’s Biofuels Association head Claudio Molina.

Argentina represented two-thirds of the total US biodiesel imports of 916M gallons in 2016, followed by Indonesia and Canada, according to US government data.

The EU has previously placed anti-dumping duties on Argentinian and Indonesian biodiesel, and both have filed complaints against the measure with the World Trade Organization, which ruled in Argentina’s favour in early 2016.