Westpac Bank says new scam detection systems monitoring offshore online transactions have saved customers more than $6 million during the past two months alone.

In a trial last year, blocking selected online stores mainly selling diet pills, Westpac says it prevented more than 11,000 potential scams saving $1.2 million.

Now it has expanded the program to protect Australians from many overseas retailers targeting Australians with false advertising for popular products like diet pills, supplements, dating subscriptions and business services.

The company’s scam detection technology analyses transaction patterns, previous reports from other customers as well as merchant behaviours and attributes, to either add or remove vendors from these high-risk lists. If a scam is detected while a customer is making an online payment, the process will be blocked and customers will be notified via text message.

Westpac says that in more than 99 per cent of cases, customers did not proceed with the transaction after getting the alert.

Chris de Bruin, Westpac chief executive of Consumer & Business Banking said online shopping scams are on the rise with scams getting more sophisticated.

“With our research showing these scams are costing Australians hundreds of millions each year, we’re ramping up our investment in technologies which will help detect scams and prevent customers getting swindled,” he said.

During last year’s trial, more than 11,000 potential scams were blocked for 4000 customers, saving more than $1.2 million. Since January, the bank says it has saved an additional $6 million, on behalf of stopped 69,000 customers, saving an average of $87 each transaction.

Westpac head of Fraud, Ben Young said: “We encourage customers to remain vigilant when shopping online. If a customer believes they have been the victim of a scam they should call us as soon as possible. We have a specialist team of staff trained to assist customers impacted by scams.”

The company plans on expanding this to more merchants to help customers from losing out on their money and also to scale up on fraud-protection mechanisms. The scam blocks work on Westpac debit and credit cards as well as third-party mobile wallets.