Autonomia ordinamentale e pluralismo giuridico: il divieto ne bis in idem tra Engel criteria e principio di proporzionalità.

The paper aims to analyze the evolution of the “ne bis in idem” prohibition in the European Union law, with a rereading in a "substantial" key, based on the so called “Engel criteria”, from recent european and national jurisprudence. More precisely, according to this interpretative orientation, this prohibition could be violated regardless of the "criminal" qualification attributed to penalties or judicial procedures aimed at punishing the same fact several times. On the basis of these considerations, it will be asked if this prohibition can operate today where competitions are sanctions or proceedings originating from different legal systems. In particular the possible violations of “ne bis in idem” principle will be analyzed regarding all the relations between the sports legal system and the state legal system