Diego García-Sayán, UN Special Rapporteur on the Independence of Judges and Lawyers
Corruption has a direct impact on the validity of human rights, largely because of two reasons.
On one side, corruption deprives societies of important resources that could be used for basic needs, such as public health, education, infrastructure, or security. The OECD has indicated that the cost of corruption, in its different modalities, constitutes more than 5% of the global GDP.
On another side, corruption has direct damaging consequences in general on the functioning of state institutions, and in particular on the administration of justice. Corruption decreases public trust in justice and weakens the capacity of judicial systems to guarantee the protection of human rights, and it affects the tasks and duties of the judges, prosecutors, lawyers, and other legal professionals.
By seeking impunity, corruption has a devastating effect on the judicial system as a whole. One of the goals of human rights is to fight corruption and its implications on the administration of justice, as is to act against corruption through an independent and strong administration of justice. For this, the United Nations Convention against Corruption is a fundamental instrument for the protection of human rights.
In my report presented last year at the General Assembly, I established that "as a key tool to fight against corruption, the Convention should also be considered as a fundamental international instrument for the protection of human rights, and that it should merit, consequently, the permanent attention of the bodies competent in this matter". 
Corruption in the Judicial System
Corruption undermines the core of the administration of justice, generating a substantial obstacle to the right to an impartial trial, and severely undermining the population's trust in the judiciary.
Corruption has a variety of faces, bribery being only one of them, another being political corruption, much more unattainable and imprecise. Its broad range of action enables it not only to influence the judicial system, but all the sectors of state administration as well.
Illicit interferences with justice can also be violent, particularly when perpetrated directly by members of organised crime. These forays are intended to secure specific objectives, such as the closing of a particular case, or the acquittal of a given individual.
Corruption and the Historical Responsibility of Justice
Internal norms in different states and several relevant international instruments establish different ranges of obligations to confront corruption. However, while judicial systems are themselves the target of corruption and organised crime, it is precisely within judicial systems that societies have their main instrument to prevent and fight corruption.
Article 11 of the United Nations Convention against Corruption - a fundamental international treaty - emphasizes the decisive role of the judicial branch in the fight against corruption, and establishes that in order to carry out this role effectively, the judicial branch itself must be free of corruption, and that its members must act with integrity. Substantive guidelines on matters of internal organization, which are fundamental to prevent and confront corruption, have been included in the Convention.
There are core obligations in the Treaty on international cooperation between judicial and prosecutorial bodies of sovereign States (Chapter IV) which are unprecedented in a multilateral treaty. For example, it contains substantive and operational obligations in extradition matters, the transfer of convicted persons and judicial assistance, referral of criminal proceedings from one country to another, joint investigations, and, in general, clear substantive obligations in matters of cooperation for compliance with the law.
Judicial Integrity and the Fight against Corruption
In 2016, the United Nations Office on Drugs and Crime launched a global programme to promote a culture of lawfulness. It includes the creation of a Global Judicial Integrity Network to share best practices and lessons learned on the fundamental challenges and new questions relating to judicial integrity and the prevention of corruption.
This is an important step for the creation of a common language and a common perspective amongst different domains of the United Nations. In my capacity as Special Rapporteur, I have already expressed my full disposal to collaborate in the implementation of this programme.
 United Nations, A/72/140. 35 July 2017