Wilmar International said the company’s records on value-added tax refund claims in Indonesia “will stand scrutiny”, reinforcing an earlier statement that the company’s local units have complied fully with tax rules.

“Questions of fictitious or false claims made by the group do not arise,” Wilmar said in a statement to the Singapore stock exchange today. “Internal records in respect of the VAT refund claims viz-a-viz export sales will stand scrutiny.”

Wilmar, the world’s biggest palm-oil trader, fell by the most in 17 months in Singapore trading today after the Jakarta Globe reported that operations in Indonesia are being probed by the authorities. The possible tax fraud involves as much as 3.6 trillion rupiah ($545 million), the Globe said yesterday, citing documents provided by lawmaker Bambang Soesatyo.

The company said yesterday that the claims in the media reports are untrue and unsubstantiated. “VAT refund claims in Indonesia involve straightforward procedures,” said today’s statement, which was issued after the close of trade.

Wilmar fell 7%, the biggest one-day drop since December 2008, to close at $5.76 today. The decline of Singapore’s second-largest stock by market value helped drag the benchmark index down 2.4%.

The company is the largest exporter of palm oil from Indonesia, which is the largest producer of the commodity used in cooking, cosmetics and as a fuel additive. The company is also the biggest provider of cooking oil in China.

“All claims for VAT refund are subject to a verification process by the relevant authorities,” today’s statement said. Local Wilmar units “exported more than US$3 billion worth of palm oil in each of the last three financial years, thereby entitling these subsidiaries to claim the excess of the VAT paid on the cost of these sales for each of those years.”