According to screenshots that appeared this week, Facebook Messenger is already equipped to handle fast mobile payments with a user's registered card details.
Andrew Aude, a computer science student at Stanford University, discovered the hidden feature using iOS and OS X tool Cycript.
According to Aude, it is easy to transfer money using Facebook Messenger. Users can tap to attach money to a message, much like a photo, then choose from any registered card to make the payment.
Payments are private and not published to the News Feed. There is no need to register bank details, though it is not clear how Facebook finds the bank details of the recipient to transfer the cash.
This latest revelation all but confirms that Facebook is developing a payments feature for its Messanger app. The company hired former PayPal president David Marcus in June. And last month, reverse engineer Jonathan Zdziarski discovered Messenger had the ability to store credit card information.