The document discusses the ne bis in idem principle in EU competition law. It provides that the ne bis in idem principle, which prohibits double jeopardy, is recognized as a general principle of EU law based on its inclusion in the European Convention on Human Rights and national laws of EU members. In EU competition law, the principle prevents undertakings from facing penalties for the same anti-competitive conduct in proceedings by both the European Commission and national competition authorities. However, it does not apply when proceedings involve authorities outside of the EU.