Bitcoin’s march into the mainstream continues, with an Australian firm launching the country’s second two-way bitcoin ATM in Melbourne.

Australia’s second two-way bitcoin ATM has gone live in central Melbourne, allowing locals to buy and sell the digital currency and exchange it for cash.

The machine, installed in the Emporium shopping centre on Lonsdale Street overnight, arrives six weeks after the launch of the first in central Sydney.

Chris Guzowski, the head of ABA (Australian Bitcoin ATMs) Technology, the firm behind the two machines, said the Sydney machine had handled hundreds of deals worth tens of thousands of dollars.

He would not provide a more accurate figure, but said some users had made single transactions worth up to $5000.

Unlike online bitcoin exchanges, which can be complicated and marred by delays, Mr Guzowski said the ATMs were simple and processed deals instantaneously.

Users can register an account in about five minutes. The machine scans their government-issued photo ID, such as a driver’s licence, and uses facial recognition technology to verify that their face matches the photo.

Users also scan their palm on the machine, which is used along with a PIN and their phone number to verify their identity in future transactions.

Once an account is set up, users can buy or sell bitcoins at the market price. They can add bitcoins to their virtual wallet by feeding in cash or cards, and can sell them to extract cash.

ABA Technology makes money in a similar way to a foreign exchange, by buying and selling at different rates and claiming the difference.

One bitcoin is currently worth $613 – an appreciation in value of about $120 since the launch of the Sydney machine six weeks ago.

The company bought the first two machines from RoboCoin, the US firm credited with providing the world’s first such ATM, which appeared in a Vancouver cafe in October. RoboCoin sells the terminals for $US20,000 ($A21,640) apiece.

Spokesman Sam Glaser has previously told AAP that “even the slowest” of RoboCoin’s ATMs would handle more than $US1 million in transactions per year.

Yet experts have questioned the timing of the rollout, pointing to moves by banks such as NAB and the Commonwealth Bank to close the accounts of clients involved in the bitcoin trade, citing unacceptable risk.

Professor David Glance, a bitcoin expert and head of software practice at the University of Western Australia, has also said the heavy security in the ATMs could strip bitcoin of one of its key selling points: anonymity.

“This is a really bad time to be launching devices like this,” he told AAP in April.

Guzowski is undeterred. He plans to roll out the ATMs across the country, with the next pegged for Brisbane in June.