The scam has only recently been discovered by the operators of a small number of major tourist attractions in Victoria and NSW. But leading tourism industry figures fear the size and scale of the ticketing fraud could be immense.

In Victoria, nine leading tourism businesses have in recent months had to refund almost $400,000 to the legitimate owners of credit cards used by the syndicate to buy tickets to attractions such as the Eureka Skydeck, Sovereign Hill in Ballarat and the Peninsula Hot Springs near Rye.

"Clearly this is likely to be just the tip of the iceberg. I would imagine we are talking millions of dollars nationally," warned Victorian Chamber of Commerce and Industry chief executive Mark Stone, who also leads the state's tourism industry council and wants members affected by the scam to contact police.

The scam has also hit major Sydney tourist attractions such as the Harbour Bridge's BridgeClimb, which had to make tens-of-thousands of dollars in credit card refunds late last year. BridgeClimb's chief financial officer Max Futeran said: "I reckon this is a multimillion-dollar problem ... there's a number of people in the industry unaware this has been happening."

He said tourism businesses across the country should be checking their recent financial records to determine whether there had been a recent spike in credit card "charge backs".

The revelation of the tourism scam comes as Australian law enforcement agencies are examining the organised subversion of Australia's visa system by overseas criminal groups to facilitate large scale fraud.

Law enforcement sources say that the crime groups have dispatched credit card fraudsters to Australia by working with corrupt education and migration agents who help the fraudsters obtain student visas.

Fairfax Media has learned that the crime syndicate running the tourism ticketing scam is recruiting Chinese students located in Australia to work for it as "agents" to promote discounted tickets via their own WeChat networks.

The scam involves tourist attraction tickets bought with stolen credit cards being on-sold at discounted rates to unsuspecting Chinese tourists via the WeChat social media platform, which is used by about 800 million Chinese.

The scam affects tourism operators in three ways: Firstly, they are having to give refunds to the legitimate owners of credit cards which have been fraudulently used. Secondly, they are being stung by bank fees of up to $70 for each refund. Lastly, they are losing genuine ticketing revenue each time a fraudulently-bought ticket has successfully been used to access their attraction.

"It's a triple whammy," said one leading Victorian tourism industry leader.

Eureka Skydeck general manager John Forman said the scam had cost his business $44,000 in credit card refunds and lost ticketing revenue. He said those behind the scam were showing no signs of stopping.

"In March, 13 per cent of our online ticket sales were bought with stolen credit cards. In February it was 10 per cent and January it was 7 per cent," Mr Forman said. "In my opinion this has the potential to close down a lot of small operators."

Brook Ramage, head of operations at Peninsula Hot Springs, said his business had lost about $30,000 to the scam. Mr Ramage said his business and others similarly affected are now investing in better IT security to try to stop the fraudulent credit card purchases.

In the meantime, Mr Ramage said many tourism businesses have to manually check online purchases each day in order to identify tickets or vouchers that have been bought using suspect credit cards.

This has led to Chinese tourists at several attractions across Australia now being asked to produce identification and show the credit card used to purchase tickets before being allowed entry.

"You have to feel sorry for those people because they are paying for a ticket and not knowing it has been bought with a stolen credit card," Mr Ramage said.

Other Victorian tourism business affected by the scam include the Phillip Island Nature Park, Skybus and Global Ballooning. Discounted tickets for events such as Sydney's Easter Show, the Avalon Airshow and Victoria's Spring Racing Carnival have also been promoted on WeChat, raising concern that may have also been targeted.

Mr Futeran and Mr Forman said their companies had reported the scam to New South Wales and Victorian police.

Police are understood to have recently traced the identity of one of the syndicate's suspected ringleaders and put out an alert to Border Force officials to stop him from leaving Australia to return to China.

A request has been made to freeze the suspect's Australian bank accounts.

But until the syndicate is put out of business, Mr Futeran warns: "If the price for a ticket on WeChat looks too good to be true it probably is."