Hong Kong (CNN) -- Australian police say seven people have been arrested in Romania as part of a joint international criminal investigation into the largest credit card data theft in Australia's history.
Among those detained by the Romanian investigative agency was Gheorghe "the Carpathian Bear" Ignat, a Greco-Roman heavyweight wrestling champion.
Officials say the year-long investigation, dubbed "Operation Lino," involved 14 countries and uncovered phony credit card transactions worth AUD30 million (US$31 million). The criminal syndicate had access to half a million Australian credit cards, the Australian Federal Police (AFP) stated in a press release.
"Initially we were approached by the banking industry, who had noticed irregular charges on credit cards... All of the information led back to Romania," an AFP official told CNN. "We then built a brief of evidence to provide to the Romanian police, which allowed them to carry out an investigation in Romania."
The majority of victims were small businesses, service stations, petrol stations and corner stores, who often have less-secure payment gateways. The hackers profited by selling data to do "Card Not Present'"(CNP) transactions -- the use of account information without the physical card being involved -- or to create counterfeit credit cards. They then carried out thousands of counterfeit transactions across the globe in Asia, Europe and the U.S., according to the AFP.
"There's very good consumer protection here in Australia. The AUD30 million was spread across banks, credit unions and the membership and no cardholder lost money," Heather Wellard of the Australian Bankers' Association told CNN. "The important thing is banks' systems were not compromised."
Statistics from a self-regulatory body in Australia's payment industry show that of the one million cases of bank card fraud reported in Australia in 2011, 65% were perpetrated overseas.
Latest industry figures also show that CNP fraud in Australia is on the rise, accounting for 71% of all fraud value on Australian-issued bank cards.
"Such crimes tend to come from overseas," the Australian police told CNN. "This same group has targeted businesses in other countries as well."
Earlier this year, the Attorney-General of Australia, Nicola Rox acknowledged the increased danger of identity theft and fraud posed by cyber criminals on the internet.
"We're no longer just dealing with guards and gates, bombs and bullets when we talk about defending our nation and its secrets," Rox said. "We're now fairly and squarely working in an online environment. And this has created a whole new dimension of both opportunity and threat."
In July, Australia's Parliamentary Joint Committee on Intelligence and Security began an ongoing inquiry into potential reforms of national security legislation to battle cyber crimes.