Dutch authorities probe Bosnian war criminal's courtroom suicide

"Slobodan Praljak is not a war criminal. I am rejecting your verdict with contempt," Praljak shouted defiantly.

He then tilted his head back and drank from a small vial. As the judge appealed for him to sit down, Praljak declared: "I have taken poison."

The judge, looking disconcerted, suspended proceedings. The International Criminal Tribunal for the former Yugoslavia confirmed later Wednesday that Praljak had been given immediate medical help in the courtroom -- which was declared a crime scene -- before being taken to the hospital, where he died.

Authorities in the Netherlands were on Thursday urgently investigating what the substance was and how Praljak was able to obtain it while being held in UN detention.

The dramatic courtroom scene unfolded as the work of the UN tribunal, set up to prosecute crimes committed during conflicts in the Balkans in the 1990s, came to a close after more than 20 years.

Wednesday's appeal hearing, which reaffirmed the sentences imposed in 2013 on Praljak and five other former Bosnian Croat leaders for crimes against humanity and war crimes and almost all their convictions, was the tribunal's final ruling and it will formally close at the end of the year.

Significantly, the appeal judges upheld the findings of an earlier trial that implicated the Croatian regime under then-President Franjo Tudjman in a criminal conspiracy with the goal of "ethnic cleansing of the Muslim population" of parts of Bosnia to ensure Croatian domination.

The Bosnian Croat leadership, along with Croat leaders, wanted to make this territory part of a "Greater Croatia," the ICTY said when the case first went through the court.

How did Praljak obtain poison?

Dutch authorities are now investigating the apparent security breach which allowed Praljak to take his own life. The ICTY said only that he had drunk "a liquid" and quickly fallen ill.

Croatian lawyer Goran Mikuličić told CNN's local affiliate N1 that "anyone could have brought him a bottle of poison easily." He said family, friends, journalists and lawyers were allowed to visit Praljak but that only lawyers were allowed to take bags into the detention facility.

Praljak isn't the first war criminal or suspect to kill himself while being detained in the ICTY detention units.

Milan Babić, the president of the self-proclaimed "Serb Republic of Krajina" in Croatia, killed himself in 2006 after being convicted of crimes against humanity and war crimes against Croat civilians during the war in Croatia.

War crimes suspect Slavko Dokmanovic was found hanged in his cell in 1998 as he awaited the verdict in his trial.

Former Yugoslav leader Slobodan Milošević, who faced charges of genocide, crimes against humanity and other war crimes for his role in the conflicts in Bosnia and Herzegovina, Croatia and Kosovo, died in 2006 while on trial at The Hague.

The official investigation into his death confirmed that non-prescribed pills were found in his cell, but couldn't prove his intent to take his own life.

However, Florence Hartman, a former spokeswoman for the chief prosecutor at the ICTY, told the online edition of Bosnian magazine Start that someone had smuggled pills to Milošević during his stay at The Hague. Milošević took the pills, which counteracted his blood pressure medication, in order to worsen his health and die before being convicted, she is quoted as saying.

Edo Batlak, a former prisoner at one of the concentration camps the former Bosnian Croat leaders were convicted of creating, told N1 he believed Praljak's action was influenced by his pre-war role as a theater director.

"Praljak is a director by profession. So this aligns with his profession, he wants to be remembered by it," he said.

Praljak, who was detained in 2004, had already served two-thirds of his 20-year sentence, for offenses committed between 1992 and 1994, and would have been eligible for release in the coming months.

What's the response in Croatia and Bosnia?

Despite being a convicted war criminal, Praljak still commands significant support in Croatia, in an indication of how the scars of the 1990s conflicts are yet to heal fully.

The Parliament of Croatia, or Sabor, began Thursday's session with a moment of silence to honor Praljak and all war victims. The Parliament's President said all represented parties represented in the chamber agreed that the verdict had been wrong and unjust.

Representatives of the Social Democratic Party of Croatia and the liberal GLAS party, were not present for the minute of silence.

Croatia's Prime Minister, Andrej Plenkovic, had already offered his condolences and those of his government, following news of Praljak's death on Wednesday afternoon.

About 1,000 Bosnian Croats gathered in a square in the southern Bosnian town of Mostar -- where some of the fiercest fighting occurred in the 1990s -- late on Wednesday to light candles in support of Praljak, Reuters news agency reported.

The other five former Bosnian Croat leaders whose sentences were affirmed by the Appeals Chamber include Jadranko Prlić, prime minister of the self-proclaimed "Croat Republic of Herzeg-Bosnia," who was given 25 years in prison. Prlić led Croat separatists within Bosnia who wanted a part of Bosnia to be annexed to Croatia in collusion with Tudjman.

His niece, Lana Prlić, who is vice president of the Social Democratic Party of Bosnia, notably spoke out in support of the Hague tribunal in a statement on her personal Facebook page Wednesday morning.

"I respect and accept the verdict of the Court in the Hague," she wrote. "In our life, we have several families -- the one we choose and the one we are born into. The Social Democratic Party of Bosnia is my family that I chose as an activist in 2010. At the same time, I can't and don't want to escape the family whose surname I've carried since my birth in 1993. Everyone has to take responsibility for their crimes."

She called on politicians and those with influence in Bosnia and Herzegovina and in Croatia to respect the court and also the victims of war crimes and their families, who had suffered for years.

Croat politician Goran Beus Richembergh, of GLAS, also welcomed the verdict.

"A lawfully convicted war criminal committed suicide," he said in a Facebook statement. "The attempts of the HDZ (Croatian Democratic Union) to instrumentalize the Parliament of Croatia to reject the Tribunal's lawful verdict with a special statement, and to observe a minute of silence for a convicted war criminal, are unacceptable and scandalous."