A band of roaming Romanian criminals is using "virtually undetectable" technology to scam money from automatic teller machine (ATM) users across Sydney.
The international card skimming gang is targeting ATMs in Sydney, with at least 15 cash dispensing units hit so far and around $100,000 stolen, police say.
Detective Superintendent Col Dyson says the Romanian group, which probably came to Australia via the US, was using cutting-edge gear to rort consumers.
"These devices are very sophisticated when compared with those from the past ... It's virtually undetectable," Det Supt Dyson told reporters on Thursday.
He said the tiny devices were "forcibly jammed" into ATMs to record data, while a small camera videoed the pin number being entered.
The devices could be installed "in a matter of seconds", he said.
The fraud and cyber crime commander advised consumers to "cover the hand that is keying in the pin" to the ATM.
"They may still gain the data but that is virtually useless to them without the pin," Mr Dyson added.
He would not confirm the gang were Roma gypsies, but said most of the stolen cash had been sent to Romania.
He said one Romanian national was currently before the courts after being charged with fraud offences linked to a suspicious transaction.
Most of the targeted ATMs were in the southern suburbs and northern beaches, with units in the city's west and CBD also impacted, Mr Dyson said.
He said it was likely the gang would hit other capital cities in Australia after they moved on from Sydney.
He urged consumers who believed they had been scammed to contact police.
