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Standard Of Proof In International Adjudication


Standard of Proof is defined to be the level of certainty and the degree of evidence necessary to establish proof in proceeding. The term ‘evidence’ in both domestic as well as international law is construed as a means of establishing factual claims, however, the standard of proof required to establish such factual claims differ from forum to forum. The establishment of evidence plays a significant role in determining the outcome of the disputes.

In any general situation, some “facts” are likely to be subject to a range of interpretations and plausible explanations, and this is even more probable when the abuses investigated are as serious as genocide, crimes against humanity, arbitrary killing and enforced disappearances[1]. When such facts are questioned before the Hon’ble courts, they are judged based on the “degree of certainty” which can be defined as the standard of proof required.

Such standard of proof can range from preponderance of the evidence to proof beyond reasonable doubt.

The International Court of Justice has the authority to ascertain the existence of a fact which if proved will constitute the breach of an international obligation. In order to enable the court to make an informed decision, Article 48 of the Statute of the International Court of Justice provides that the Court shall “make all arrangements connected with the taking of evidence”.

Various other provisions are also laid down in both the Statute and the Rules of the Court which allow the Court to admit and evaluate evidence with greater freedom as compared to domestic courts. While the above-mentioned law provides the outline within which ‘evidence’ is to be dealt with by the court, the court has a wide power to fill in its own color.

The statute and the rules have left the hon’ble court with the freedom to determine its procedure depending upon a case to case basis with regards to the burden and standard of proof, admissibility of evidence, etc. The court has established various principles regarding standard of proof and admissibility of evidence in international adjudication through various landmark judgements to ensure sound dispute resolution.

Standard of Proof

Standards of proof enable the courts to “mark a point between two extremes: a mere conjecture at one end, and absolute certainty at the other”.[2] The trouble lies in determining the ideal point where the standard should be located on the scale, especially when it is to be decided on case to case basis in international adjudication. Whereas in domestic adjudication of disputes, specific and clear standards of certainty are established in the very core of the legal system. Such standards are to be applied with strict uniformity.

 Common law countries have provided the concept of ‘beyond reasonable doubt’ as a standard of proof in order to establish guilt in criminal trials. This high standard is rationally justifiable if we consider the rights of the accused that are at stake. The presumption is that it is more costly to convict an innocent person than to acquit a guilty one. Otherwise, a lower standard, a preponderance of the evidence, would seem to suffice.[3] In civil matters the standard of proof required to establish guilt of the respondent is ‘preponderance of evidence’. Wherein if the respondent is more likely to be guilty than not guilty, he will be liable. The standards are lower than criminal adjudication because the gravity of consequence is lower.

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In the author’s opinion, standards of proof are essential to prevent false accusations in common law. But can these strict standards be applied to international adjudication?

Approaches to International Adjudication of Disputes

  1. International Court of Justice (ICJ)

The provisions governing the ICJ do not provide for any predetermined standards of proof. The court in its judgments has given a variety of interpretations to the term ‘credibility of evidence’. The standard of proof is influenced by the matter being dealt with. As claims become more serious, judges tend to apply a higher standard of proof.[4]

This can be demonstrated through the two functions of the Court: (i) the declarative function and (ii) the determinative function. The declarative function deals with issues such as defining a boundary. A lower standard of proof is applied because the Court’s task is to ascertain a fact rather than determine whether an illegal act was performed. In such cases, the Court will usually have to decide which of the parties have the most evidential & plausible version of the facts. This criterion is similar to the “preponderance of probabilities”, a lower standard, that has been used in other legal proceedings that deal with the determination of a territorial or maritime frontier.[5]

Whereas a higher standard of proof  is to be established while undertaking determinative function, as responsibility for a breach of international law is to be fixed upon a state. Despite the varied practices of the court, some judges have said that it is necessary to establish a more universal and comprehensive standard of proof.[6]

  1. European Court of Human Rights (ECtHR)

Although ECtHR is not bound by its governing provisions to follow any predetermined degree of standard of proof, the precedents set by the court have reflected the standard to be “proof beyond reasonable doubt”. The “reasonableness” criteria that needs to be surpassed is defined as follows: “Not a doubt based merely on a theoretical possibility or raised in order to avoid a disagreeable conclusion, but a doubt for which reasons can be drawn from the facts presented.”[7]

The Challenges in Ascertaining the Credibility of Facts

It should also be noted that, such discretion with respect to evidence and standard of proof has been provided to the ICJ as there are various challenges in ascertaining the credibility of facts and the evidence supporting such facts as:

  1. mass violations are frequently committed in a situation of armed conflict or severe social violence which complicates the documentation of violations.[8]
  2. the state or non-state organizations that commit serious violations, the entities subject to scrutiny tend to be particularly adept at destroying evidence and concealing the identities of perpetrators.[9]
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It is essential that the appropriate standards of burden of proof are identified. In the recent past the question of appropriate standards of burden of proof have been addressed in several matters before the international adjudicatory authorities. Most notably, the retraction by Justice Goldstone with some of the findings of the UN Fact-Finding Mission into the Gaza Conflict naturally caused observers to review its methodology and standards.[10]

In 2010, The Rwandan government accused the Office of the High Commissioner for Human Rights (OHCHR) of using the “lowest possible standard of evidence”, since the mapping report by the office included allegations of genocide against Hutus. It was argued by the government that if the accusation is of a grave offence, only a “beyond reasonable doubt” standard could be made applicable.

The Corfu Channel Case

In the landmark judgement of Corfu Channel, two British destroyers suffered damage after they struck mines in Albanian waters. An application was filed, instituting proceedings against the Republic of Albania, seeking that Albania should be held liable and must make reparation or pay compensation for the damage and loss of life suffered. While holding Albania responsible for the damage and loss of human life suffered by the United Kingdom, the Hon’ble International Court of Justice opined that:

“the fact of this exclusive territorial control exercised by a State within its frontiers has a bearing upon the methods of proof available to establish the knowledge of that State as to such events. By reason of this exclusive control, the other State, the victim of a breach of international law, is often unable to furnish direct proof of facts giving rise to responsibility. Such a State should be allowed a more liberal recourse to inferences of fact and circumstantial evidence. This indirect evidence is admitted in all systems of law and its use is recognized by international decisions.”

Another important observation made by the Hon’ble Court in the case was that “the proof may be drawn from inferences of fact provided that they leave no room for reasonable doubt.”


Varied standards of proof are being applied in international adjudication of disputes, ranging from preponderance of the evidence to proof beyond reasonable doubt- depending upon the various stages of adjudication and depending upon the nature of the dispute itself.  It is observed that domestic and international adjudication of disputes differ in the very nature of disputes, the parties to the dispute and the consequences of the decision, where the decision affects numerous international adjudications. In such a situation it is very difficult to establish a rigid framework for standards of proof and the degree of certainty required.

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In my opinion, the international adjudicatory authorities have been rightly given the authority to determine their own procedure under the statute. Owing to the different nature of disputes, the means to establish or deny credibility of evidence in international adjudication should not be compared with domestic adjudication. Further, to achieve effective decision making the most reliable method would be to establish standards of proof on a case to case basis, keeping in mind 1) The degree of liability or consequences that will result from conviction; 2) the nature of dispute;3) the prima facie credibility of fact finding.

[1] Standards of Proof in International Humanitarian and Human Rights Fact-Finding and Inquiry Missions, Stephen Wilkinson.

[2] K. Del Mar, The International Court of Justice and Standards of Proof, Heathcote The Lasting Impact of the Corfu Channel case (Routledge, 2011).

[3] N. Combs, Fact Finding Without Facts: The Uncertain Evidentiary Foundations of International Criminal Convictions, Cambridge University Press, 2010, at 355.

[4] K. Del Mar, The International Court of Justice and Standards of Proof, in: Bannelier, Chistakis, Heathcote (eds), The ICJ and the Development of International law. The Lasting Impact of the Corfu Channel case (Routledge, 2011).

[5] Del Mar, supra note 28, at 4, Northern Sea Continental Shelf (Federal Republic of Germany/Denmark; Federal Republic of Germany/Netherlands), Judgment, ICJ Reports 1969, p. 3, p. 22, para. 18 and 20; Land and Maritime Boundary Between Cameroun and Nigeria, supra note 40, p. 359,para. 84,

[6] Oil Platform, Judge Higgins, pp. 233-234, paras. 30 and 33, and Judge Buergenthal, p. 286, para.41, supra note 82,

Application of the convention on the Prevention and Punishment of the Crime of Genocide, supra note 97, para. 209.

[7] Ribitsch v. Austria, ECHR, 1974, § 104.

[8] L. Sunga, How Can UN Special Procedures Sharpen ICC Fact Finding, The International Journal of Human Rights,

15:2, 187-205, at p. 187.

[9] L. Sunga, How Can UN Special Procedures Sharpen ICC Fact Finding, The International Journal of Human Rights,

15:2, 187-205, at p. 187.

[10] Reconsidering the Goldstone Report on Israel and war crimes, Washington Post (2 April 2011). docs/16session/A.HRC.16.24_AUV.pdf.

Cite this article (The Bluebook 20th ed.)-

Piyush Singh Phogat, Standard Of Proof In International Adjudication, Ex Gratia Law Journal, (September 8, 2020),

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Piyush Singh Phogat
Student - Gujarat National Law University