National Australia Bank is to close down accounts held by people trading in bitcoin due to the "unacceptable level of risk" posed to its business and reputation.
The bank has joined others, such as Bank of Ireland and BMO, in taking a hardline policy on bitcoin-related accounts.
NAB has informed affected customers of its change of heart in a letter, saying that it has a responsibility and commitment to continually review its risk profile.
"NAB has recently conducted a review of businesses that trade in digital currencies and has determined that digital currency providers pose an unacceptable level of risk, both to our business and reputation," says the letter, sent to AusBitcoins and seen by Coindesk. "As a result of this review, NAB has decided to stop providing banking services to you and will close your accounts, effective 2nd May 2014."
The move comes just a month after Japanese bank Mizuho found itself caught up in the fall-out from the collapse of MT Gox. As the banker to the defunct bitcoin exchange, Mizuho has been named in two of the numerous lawsuits being brought against the bankrupt company in the US and Canada.