The EU is investigating Belgium’s tax deals with multinational corporations, potentially dragging dozens more companies into widening probes of sweetheart fiscal pacts handed out by national governments.

Amazon’s tax affairs are back in the limelight as the European Union publishes details of its probe into a sweetheart deal with Luxembourg.

The European Union’s new anti-trust chief said the EU is braced for a legal battle with governments embroiled in its probe of sweetheart tax deals for multinationals from Apple to Amazon.