Lawyers representing the alleged financier of the 1994 Rwandan genocide, Felicien Kabuga, have requested that charges against him be dropped on the grounds he is unfit for trial.
In a May 6 filing to the UN court's branch in Tanzania, lawyer Emmanuel Altit said that medical reports prove that his 84-year-old client could not withstand trial.
"Pursuing the case under these conditions would constitute a serious breach of Felicien Kabuga's rights and would put into question the fairness of the trial," the document, seen by AFP Sunday, states.
"The court and the parties involved now have enough evidence to rule that the case must be stopped," the lawyer added.
Altit asked that in the event the court rejects his motion for dismissal, Kabuga should be freed on bail.
Once one of Rwanda's richest men, Kabuga allegedly helped set up hate media that urged ethnic Hutus to "kill the Tutsi cockroaches" and funded militia groups.
He was arrested in France last May and transferred to the court in The Hague in October to answer to charges of playing a key role in the killing of 800,000 Tutsis and moderate Hutus.
The Rwandan faces seven counts including genocide, incitement to genocide and persecution.
In a recent interview with AFP, Kabuga's eldest son, Donatien Nshimyumuremyi, said his father's health had significantly deteriorated.
"We can say without a doubt that he is physically and mentally unfit for trial and also to assist his attorney," he said.
Nshimyumuremyi said that apart from being frail and ill, his father had hurt himself after falling twice in prison.
His trial is set to start in several months.
The UN says 800,000 people were murdered in a 100-day rampage that began in April 1994 in Rwanda, in scenes of horror that shocked the world.
An ally of Rwanda's then-ruling party, Kabuga allegedly helped create the Interahamwe Hutu militia group and the Radio-Television Libre des Mille Collines (RTLM), whose broadcasts incited people to murder.