Australia's government said Wednesday there would be a full investigation into a sharp jump in the Australian dollar seconds before the country's central bank surprised some investors by holding rates steady. Treasurer Joe Hockey said he phoned Reserve Bank of Australia Governor Glenn Stevens on Wednesday morning to discuss the movement, which is being investigated by market regulator the Australian Securities and Investments Commission. "I was, like he was, concerned about reports that there have been extraordinary trades before the release of the Reserve Bank decision yesterday," Mr. Hockey said. "I'm satisfied that that investigation will be properly undertaken." Traders at Citigroup said the move, which correctly anticipated the direction of the Australian dollar, raised "a few questions about the possibility of a data leak." Many investors and traders had expected the RBA to cut its benchmark interest rate from a record low 2.25%. Falling rates tend to make a currency relatively less attractive to hold. The central bank kept rates unchanged, citing concerns about frothy housing prices. In May 2014, an employee of Australia's government statistics office and an employee at one of the country's biggest banks were arrested in a case alleging insider trading that used leaked government data. Josie Cox contributed to this article.