This was only the third time the central bank had intervened in the foreign exchange market to support the local currency since 2001.
"We provided some liquidity on Friday night,'' a spokesman for the RBA said.
"Did we buy some Australian dollars on Friday night? Yes we did.
"The FX market was very illiquid.''
The RBA source said the central bank was not defending any key level in the Australian dollar, which fell to US60.55c on Friday night for the first time since April 2003.
The currency also fell to 55.10 Japanese yen during offshore trade, its lowest point since the end of World War II.
"We're not defending any particular level, we're providing liquidity,'' the spokesman said.
The RBA spokesman said the central bank would intervene again if trading conditions were illiquid.
Asked if the RBA would intervene in the market again, he replied: "If the market is illiquid we will be doing the same''.
The RBA spokesman said he could not recall if the European markets were open during the Australian dollar intervention.
The central bank intervened in the currency market in September 2007, in the early days of the credit crunch, and in 2001, when the Australian dollar was worth less than US50c.
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