FILE PHOTO: BHP Billiton Chief Executive Andrew Mackenzie is silhouetted against a screen projecting the company's logo at a round table meeting with journalists in Tokyo, Japan June 5, 2017. REUTERS/Kim Kyung-Hoon

MELBOURNE (Reuters) - The state of Western Australia said on Monday an audit had found global miner BHP Group underpaid royalties on iron ore shipments sold via its Singapore marketing hub stretching back over more than a decade.

BHP quickly disputed the claim, saying long-standing deductions it makes to account for the cost of selling Western Australia iron ore had been consistently audited and accepted by the state as part of calculations on how much the world’s biggest miner owed it in royalty payments.

State Treasurer Ben Wyatt told reporters on Monday the underpayments added up to around A$200 million-A$300 million ($143 million-$215 million) covering 2004-2016.

“The State Government is negotiating with BHP to resolve the matter in the best interests of the State,” Premier Mark McGowan’s office said in a statement.

In its own statement, BHP said the Western Australia Mines Department had recently queried the historically accepted deductions for costs.

“It is concerning that previously audited and accepted payments to the government are now being revisited and BHP is working with the Mines Department to resolve this matter,” it said.

BHP reached a deal to pay $390 million in additional taxes to the Australian government in November to settle a long-running tax dispute over the miner’s Singapore hub on its income from 2003-2018.