Application and Violation of the Ne Bis in Idem Principle

Zinaić v. Croatia – European Court Finds a Violation of the Ne Bis in Idem Principle Due to Criminal and Misdemeanour Proceedings Concerning the Same Event

Ruostalianen v. Finland – Violation of the Ne Bis in Idem Principle Due to Misdemeanour and Administrative Proceedings Concerning the Same Event

On 5 February 2026, the European Court of Human Rights (hereinafter: the “European Court”) delivered its judgment in Zinaić v. Croatia, application no. 35519/21, finding a violation of Article 4 of Protocol No. 7 to the Convention for the Protection of Human Rights and Fundamental Freedoms (hereinafter: the “Convention”).

The case is relevant to the application of the ne bis in idem principle, namely the right of an individual not to be prosecuted, tried or punished twice for the same conduct.

The European Court reiterated that the fact that the same conduct may constitute both a misdemeanour and a criminal offence does not, in itself, mean that two separate and unrelated proceedings may be brought against the same person and result in two sanctions.

Factual background

The police station in Krk brought proceedings against the applicant before the Misdemeanour Court in Rijeka for disturbing public order and peace.

The applicant was found guilty in the misdemeanour proceedings and fined. Among other things, it was established that he had shouted and struck another person, M.P., in the head with his fist, causing M.P. to fall to the ground.

The applicant lodged an objection against the misdemeanour order, disputing the commission of the offence. He subsequently withdrew his objection, following which the misdemeanour order became final.

M.P. subsequently brought criminal proceedings against the applicant for the criminal offence of causing bodily injury.

In the first set of proceedings, the Municipal Court in Rijeka dismissed the charge, finding that the criminal proceedings concerned the same event and the same acts for which the applicant had already been convicted in the misdemeanour proceedings.

However, the County Court in Rijeka upheld M.P.’s appeal and quashed the first-instance judgment.

In the renewed proceedings, the Municipal Court in Rijeka found the applicant guilty of causing bodily injuries to M.P. and sentenced him to a four-month suspended prison sentence. The judgment was upheld on appeal.

After the Constitutional Court dismissed his constitutional complaint, the applicant brought his case before the European Court of Human Rights.

What does the ne bis in idem principle mean?

Article 4 of Protocol No. 7 to the Convention protects an individual against being tried or punished again for an offence in respect of which he or she has already been finally acquitted or convicted.

The protection afforded by this provision is not limited to the prohibition of double punishment. It also encompasses the right of an individual not to be prosecuted or tried twice in respect of the same facts.

At the same time, the European Court does not consider that the Convention absolutely prohibits criminal and misdemeanour proceedings arising from the same event.

States have a certain degree of freedom in choosing how to respond to different forms of socially unacceptable conduct. However, where two proceedings are brought in respect of the same conduct, they must be sufficiently closely connected in substance and in time so that they can be regarded as forming part of a single, coherent whole.

The different purposes of the proceedings must be complementary, while the consequences for the person concerned must be proportionate and foreseeable.

The European Court has developed these principles in detail, notably in A and B v. Norway.

Why did the European Court find a violation in Zinaić?

In Zinaić v. Croatia, the European Court first established that the idem element was present, meaning that both sets of proceedings concerned the same facts.

The misdemeanour and criminal proceedings concerned the same event and the same conduct of the applicant – the physical attack on M.P.

The fact that the consequences of the assault, namely the bodily injuries suffered by M.P., were additionally described in the criminal proceedings did not alter the European Court’s conclusion. Those injuries resulted from precisely the acts for which the applicant had already been finally punished in the misdemeanour proceedings.

The European Court then examined whether there was a sufficient degree of connection between the two proceedings.

It did not accept the argument that the misdemeanour and criminal proceedings pursued complementary purposes. According to the Court, both proceedings largely concerned the same acts of the applicant, and therefore could not be regarded as forming a sufficiently connected whole.

Of particular importance was the fact that the applicant could not have foreseen that, after the misdemeanour order had become final, he would subsequently be tried in criminal proceedings for the same conduct.

The European Court therefore concluded that the two proceedings were not sufficiently connected in substance to constitute part of an integrated system of sanctions under Croatian law.

The applicant consequently suffered disproportionate prejudice, as he was subjected to two sets of proceedings and two sanctions in respect of the same conduct.

Connection with Maresti v. Croatia

The significance of the Zinaić judgment is further underscored by the fact that the European Court had already addressed a very similar issue in Maresti v. Croatia in 2009.

In that case, the European Court likewise found a violation of Article 4 of Protocol No. 7 as a result of criminal and misdemeanour proceedings concerning the same conduct.

In Zinaić, the European Court also noted the legislative amendments and changes in domestic judicial practice subsequently introduced in Croatia with the aim of preventing similar violations.

Nevertheless, in the present case, the Court found that the applicant had again been subjected to two sets of proceedings and sanctions concerning the same conduct.

What does the Zinaić judgment mean in practice?

The Zinaić v. Croatia judgment confirms the importance of the ne bis in idem principle in situations where the same conduct may simultaneously constitute a misdemeanour and a criminal offence.

For the purposes of this principle, it is not decisive merely that the misdemeanour and criminal offence are formally distinct under domestic law.

The key issue is whether the proceedings concern the same or substantially the same facts and whether there is a sufficiently close connection between them in substance and in time.

In other words, the fact that particular conduct may be sanctioned under different legal provisions does not, in itself, mean that two separate and unrelated proceedings may be brought against the same person and result in two sanctions for the same conduct.

The judgment is therefore relevant to situations in which different proceedings are brought against the same person on the basis of the same factual circumstances.

Ne bis in idem in administrative matters

The application of the ne bis in idem principle is not limited to criminal and misdemeanour proceedings.

The principle may also apply to administrative proceedings where the sanctions imposed are, by their nature, considered to constitute a “penalty” for the purposes of the Convention.

The European Court addressed this issue in Ruostalianen v. Finland, application no. 13079/03.

In that case, the applicant had used fuel in his vehicle which did not comply with the applicable requirements for the vehicle, using heating oil instead of the prescribed fuel.

The applicant was fined in misdemeanour proceedings and was also required, in administrative proceedings, to pay an additional tax-related amount which, by its nature, had the characteristics of a penalty.

The European Court applied the so-called Engel criteria and concluded that, irrespective of the formal classification of the measure under domestic law, the measure in question constituted a penalty by its nature.

The Court found that two sets of proceedings had been brought against the applicant which, in substance, were criminal in nature and concerned the same conduct.

The Court consequently found a violation of Article 4 of Protocol No. 7 to the Convention.

The judgment confirms that the ne bis in idem principle may also apply in administrative matters where the sanction imposed is, by its nature, a penalty, regardless of the formal designation of the proceedings or sanction under national law.

Application of the principle in Croatian case-law

The European Court’s judgment in Ruostalianen v. Finland was also relied upon by the Constitutional Court of the Republic of Croatia in its decision no. U-III-5981/2016 of 27 June 2017.

The case concerned Tvornica kruha Zadar d.d., which had been finally convicted in misdemeanour proceedings for violating provisions of the Excise Duties Act.

At the same time, administrative proceedings were conducted in which the company was ordered to pay a significant monetary amount to the state budget of the Republic of Croatia.

The Constitutional Court examined the nature of the measure and relied on the standards developed by the European Court of Human Rights, including those set out in Ruostalianen v. Finland.

It found that the administrative measure in question was, by its nature, a penalty and that its imposition, following the prior misdemeanour proceedings concerning the same factual circumstances, violated the ne bis in idem principle.

The Constitutional Court therefore quashed the contested decision.

This decision confirms that, when assessing whether the ne bis in idem principle applies, it is not sufficient to consider the formal classification of proceedings as administrative. Their actual nature and the nature of the sanction imposed must also be examined.

Conclusion

The Zinaić v. Croatia judgment once again confirms that the ne bis in idem principle constitutes an important procedural safeguard against repeated proceedings and punishment for the same conduct.

It is particularly significant in the context of the relationship between misdemeanour and criminal proceedings. Where two proceedings are based on the same facts, it is not sufficient that their legal classifications or purposes are formally different. It must be examined whether there is a sufficiently close connection between them so that they together form a coherent and proportionate whole.

At the same time, Ruostalianen v. Finland demonstrates that the ne bis in idem principle may also apply to administrative proceedings where the sanction imposed is, by its nature, a penalty.

These standards have also been applied in Croatian case-law, including in the decision of the Constitutional Court of the Republic of Croatia no. U-III-5981/2016 of 27 June 2017.

Accordingly, when assessing whether the ne bis in idem principle has been violated, it is not sufficient to rely on the formal designation of the proceedings or sanction. It is necessary to examine the identity of the facts, the nature of the sanction, and the connection between the proceedings in substance and in time.

The ne bis in idem principle thus constitutes an important safeguard of legal certainty and a guarantee that an individual will not, in breach of Convention standards, be subjected to renewed proceedings and punishment for the same conduct.

Luka Mrkić Law Office provides legal assistance and representation in criminal, misdemeanour and administrative proceedings, including the protection of clients’ rights and issues concerning the application of the ne bis in idem principle.

Author: Luka Mrkić, Attorney at Law