Felicien Kabuga, who is nearly 90 and has dementia, is accused of encouraging and bankrolling the Rwanda genocide.

The ruling on Monday sends the matter back to the court’s trial chamber with instructions to impose a stay on proceedings, which likely means that Felicien Kabuga, who is nearly 90 and has dementia, will not be prosecuted.

Appeals judges at the court also rejected a proposal to set up an alternative procedure that would have allowed evidence to be heard but without the possibility of a verdict.

The UN court’s chief prosecutor, Serge Brammertz, said the ruling “must be respected, even if the outcome is dissatisfying”.

Kabuga, who was arrested in France in 2020 after years as a fugitive from justice, is accused of encouraging and bankrolling the mass killing of Rwanda’s Tutsi minority. His trial came nearly three decades after the 100-day massacre left 800,000 dead.

‘Extremely disturbing’

Kabuga has pleaded not guilty to charges including genocide and persecution. He remains in custody at a UN detention unit in The Hague, but could be released as a result of Monday’s ruling.

“I think the world does not mean good for us. What mattered to us survivors following Kabuga’s arrest was at least justice,” said Francine Uwamariya, a genocide survivor, who told the Associated Press news agency that she lost her entire family at the hands of Kabuga’s henchmen.

“The trial should have continued even without Kabuga. He was the planner and financer of the genocide. The court appears to be on the side of the killer, when it should be neutral,” Uwamariya said.

Uwamariya’s sentiment was echoed by Naphtal Ahishakiye, another genocide survivor and executive secretary of Ibuka, a Rwanda survivors’ organisation, who said there was enough evidence to convict Kabuga.

“It’s extremely disturbing on the side of survivors, who will see Kabuga walking free. Justice should be felt by those wronged,” Ahishakiye said.

Ibuka has filed a case against Kabuga in Kigali, seeking court permission to sell off all of his properties to fund reparations and help survivors.

Brammertz expressed solidarity with victims and survivors of the genocide.

“They have maintained their faith in the justice process over the last three decades. I know that this outcome will be distressing and disheartening to them,” he said. “Having visited Rwanda recently, I heard very clearly how important it was that this trial be concluded.”

Brammertz said that his team of prosecutors would continue to help Rwanda and other countries seek accountability for genocide crimes and pointed to the arrest in May of another fugitive, Fulgence Kayishema, as an example that suspects can still face justice.

Kayishema was indicted by a UN court for allegedly organising the slaughter of more than 2,000 ethnic Tutsi refugees – men, women and children – at a Catholic church on April 15, 1994, during the first days of the genocide. He is expected to be tried in Rwanda.

Brammertz said his office will significantly boost assistance to Rwanda’s prosecutor general, “including through the provision of our evidence and developed expertise, to ensure more genocide fugitives stand trial for their alleged crimes”.