The European Union's competition watchdog has U.S. fast-food giant McDonald's in its sights.

The EU's executive Commission is examining allegations by trade unions that McDonald's has made unfair tax deals in Luxembourg.

EU Competition Commissioner Margrethe Vestager said Tuesday that her office is "looking into the information gained by trade unions when it comes to McDonald's in order to assess if there is a case."

The move is one of a series in the wake of the so-called LuxLeaks allegations about sweet deals for multinationals with offices in Luxembourg.

The Commission opened tax probes last year into Apple in Ireland, Starbucks in the Netherlands and Amazon in Luxemburg.

It believes that some multinationals are shifting profits between countries and depriving EU governments of tax revenues.