Philip Lowe, governor of the Reserve Bank of Australia, criticised the cryptocurrency at the Australian Payment Summit.
While saying that the central bank was interested in issuing a form of digital money potentially using the same technology that Bitcoin is based on, Mr Lowe was critical of Bitcoin itself.
"The current fascination with these currencies feels more like a speculative mania than it has to do with their use as an efficient and convenient form of electronic payment," he said.
Bitcoin "seems more likely to be attractive to those who want to make transactions in the black or illegal economy" than to regular economic actors, Mr Lowe suggested.
His comments follow an explosion in the value of Bitcoin as well as the diminishing use of cash for transactions, with many more people paying for goods online or with cards.
The digital cash jumped 25% in value after a futures market in it opened this week. Its value is now up 1,600% in the year to date, beginning the year below $1,000 (£748).
In amazement, market analysts have watched the cryptocurrency's leap from record to record in recent days, and continue to ponder whether it is a bubble waiting to burst.