The European Commission has opened a preliminary investigation into Visa's rules regarding staged digital wallets.
Initiated in June, the probe was briefly referenced in Visa's most recent regulatory filing.
Referencing "industry insiders", the Times newspaper points to concerns among regulators that some financial technology start-ups are pushing the rules too far through a desire to offer ultra-speedy payments to customers, making it difficult for Visa to check for money laundering and fraud.
The filing also reveals a lawsuit lodged in the UK by Euronet, alleging that certain rules affecting ATM access fees in Poland, the Czech Republic and Greece breach various competition laws.
Euronet is seeking damages, costs, and injunctive relief to prevent Visa and Mastercard from enforcing the rules.