The suicide of Slobodan Praljak at the UN-mandated International Criminal Tribunal for the former Yugoslavia (ICTY) is a multifaceted scandal.
On hearing that his 20-year jail term had been upheld, the ex-commander of Bosnian Croat forces said he "was not a criminal" and then drank from a bottle.
Slobodan Praljak, 72, took a drink from a flask or glass as the judge read out the verdict.
Croatian state TV reported that President Kolinda Grabar Kitarovic made a decision to cut short an official visit to Iceland and the government was holding an emergency session.
The presiding judge suspended the hearing and called for a doctor.
The court's original conviction said Tudjman played a leading role in a plan to create a small Croat state in Bosnia.
Praljak had received a confirmation of his 20-year sentence..
Dutch police, an ambulance and a fire truck quickly arrived outside the court's headquarters and emergency service workers, some of them wearing helmets and with oxygen tanks on their backs, went into the court shortly after the incident.
The groundbreaking ICTY is to finally close next month.
Several convictions for specific crimes for Prlic and the five others were reversed in the appeal, but president Judge Carmel Agius said "all six remain convicted of numerous and very serious crimes".
Praljak's case was one of the last to be decided at a tribunal for ethnic war crimes in the former Yugoslavia, the worst outbreak of violence in Europe since the end of World War II.