Ryanair has introduced a new method for passengers who booked through so-called screen-scraping websites to claim refunds for cancelled flights.
The airline claims those who booked its flights through such third party websites have been unable to get a refund directly from it.
These websites operate by using technology to make a booking on another website like Ryanair.com.
But the company says that in the last few weeks it has been "inundated" with complaints about such websites refusing to deal with or help its passengers.
"In many cases these unauthorised screen scrapers are scamming customers by overcharging customers and then booking on Ryanair's website with fake customer contact and credit card details, then claiming customer refunds directly into their own accounts, and in some cases, refusing to pass this money onto customers," said Chief Executive of Ryanair, Eddie Wilson.
As a result, Ryanair says it has put a new "customer verification" option in place that will assist these customers.
A form enabling the process to take place and a video explaining the new system is available at Ryanair.com.
Mr Wilson called for what he described as these "anti-consumer practices" to be investigated by consumer organisations and regulators.
The airline also said that it expects to have 90% of all customer cash refunds issued by the end of July.