Airline spokesman Stephen McNamara told newspaper Södermanlands Nyheter that the budget airline’s payment system had not been adapted to take account of the new Swedish law, which came into force on August 1st.

McNamara told The Local on Tuesday that customers pay ‘administration charges’ when paying with any card other than a MasterCard Prepaid. These, he said were not the same as the banned credit card booking fees:

“Ryanair does not operate a credit or debit card payment fee. Ryanair bookings may be subject to an administration charge which all passengers can avoid by using MasterCard Prepaid to complete their booking.”

The Swedish Consumer Agency (Konsumentverket) says it will investigate any complaints against the Irish airline:

“If we get reports showing in black and white that Ryanair is charging supplementary fees then we will contact them, but we have to wait until we get reports,” spokeswoman Sharon Lavie told Södermanlands Nyheter.

“This law also applies to Ryanair,” said Lavie.

She stressed that the company was bound by Swedish rules since airline tickets may be purchased from a Swedish language section on the Ryanair website.

This story was updated on Tuesday to include clarification from Ryanair.