Click to expand Image Moussa Tiangari, Niamey, Niger, June 2024. © 2024 Amnesty International 18 months ago, Niger’s military junta arrested and detained Moussa Tiangari, a prominent human rights defender in the country. Following an investigation, the United Nations is now calling for his release. The UN Working Group on Arbitrary Detention, an independent expert body that investigates cases of deprivation of liberty, found that Tiangari’s detention is arbitrary and violates international human rights law.In its opinion released on June 23, the UN working group called on Nigerien authorities to release Tiangari and provide him with reparations. It also called for an independent investigation into his arbitrary detention and accountability for those responsible.Tiangari, 56, is the secretary general of a civil society organization, Alternative Espaces Citoyens, and an outspoken critic of the military junta. He was arrested at his home in Niger’s capital, Niamey, on December 3, 2024. He was held incommunicado for two days before finally being located at the Central Service for Combating Terrorism and Organized Transnational Crime, an inter-agency law enforcement body, headquartered in the capital.On January 3, 2025, Niamey’s High Court charged him with “terrorism apology,” and “plotting against the authority of the state through collaboration with enemy powers,” among other offenses. The investigating judge ordered his pretrial detention in Filingué prison, about 170 kilometers from Niamey. Family visits require judicial authorization and, because of the distance, are limited to twice a week. In 2025, Tiangari’s lawyers unsuccessfully filed three appeals seeking his release. He is yet to stand trial.According to the UN working group, Tiangari has not been informed of the identity of the alleged terrorist group he is accused of having links to. The charges brought against him, including allegedly plotting with enemy powers, means he could face the death penalty. Since seizing power in July 2023, the junta has targeted political opponents, civil society members and journalists. The military authorities continue to arbitrarily detain former President Mohamed Bazoum and have withdrawn Niger from key regional and international accountability bodies, including the regional bloc Economic Community of West African States and the International Criminal Court.The UN working group has spoken clearly: now Niger’s military authorities should act. They should immediately release Tiangari and the other detainees who are languishing in prison because of baseless and politically motivated charges.