The European Commission announced that they have begun an investigation into Apple and a number of book publishers in order to discover if the firms had engaged in anti-competitive practices relating to e-book publishing.
European and US-based publishers including Harper Collins, Simon & Schuster and Penguin were named as the subjects of the investigation "possibly with the help of Apple," the EC added in a release.
The action follows a series of unannounced inspections at the premises of several publishers in March. The UK Office of Fair Trading had earlier closed their investigation into the industry ceding "administrative priority" to the EC investigation.
The EC said that the OFT had already made a contribution towards the e-book pricing investigation and will continue to assist.
The investigation relates to the major publishers shifting towards a so-called 'agency' model where they set the price of e-books. That move has been widely seen as an attempt to reduce the dominance of Amazon through the online retailer's heavy discounts.
"The Commission has concerns, that these practices may breach EU antitrust rules that prohibit cartels and restrictive business practices," they said.