No punishment without law. A basic principle of criminal and penal law, which is universally recognised and outlined in major human rights conventions [8, p. 1; 6, p. 226]. Article 7 of the European Convention for the Protection of Human Rights and Fundamental Freedoms (hereinafter: ECHR) states that no one shall be held guilty of any criminal offence on account of any act or omission which did not constitute a criminal offence under national or international law at the time when it was committed [5, article 7(1)]. Moreover,the penalty imposed must not be heavier than the one applicable at the time of the criminal offence [5, article 7(2)].
