Ireland’s data regulator has given Facebook six weeks to respond to an investigation that may trigger a ban on the social media giant’s transatlantic data transfers.

It follows a US High Court ruling that the transfer data probe into how the US may treat EU data can continue.

The EU is concerned that American intelligence agencies may not respect the privacy rights of EU citizens when their personal data is sent to the US for commercial use. Analysts say the ruling may trigger a halt to data flows.

Facebook Australia’s advertising money has been going to offshore countries including Ireland to avoid paying local taxes; the company