The right to freedom of opinion and expression is enshrined in Article 19 of the Universal Declaration of Human Rights.
Human Rights Committee (if the optional protocol is ratified by the state)
Special Rapporteur on the promotion and protection of the right to freedom of opinion and expression
Special Rapporteur on the human rights of migrants
Special Rapporteur on the situation of human rights and fundamental freedoms of indigenous people
UNESCO (Committee on Conventions and Recommendations)
African Commission or Court on Human Rights and Peoples’ Rights