The International Criminal Tribunal for the former Yugoslavia in the Hague has been suspended after a defendant claimed to have drunk poison after he was handed a guilty verdict.

The defendant died shortly after losing an appeal against his 20-year prison term.

Slobodan Praljak, one of six high-level wartime Bosnian Croat leaders appealing to the court, was given a 20-year sentence in 2013 for crimes in East Mostar.

Upon hearing that the original sentence had been upheld, he was seen standing up and appearing to swallow something while making an elaborate gesture. He is reported to have told the judge that he had taken poison.

Presiding judge Carmel Agius immediately suspended the proceedings and an ambulance was called.

"Okay," the judge said. "We suspend the... We suspend... Please, the curtains. Don't take away the glass that he used when he drank something."

BREAKING: UN court suspends Bosnian Croat appeal as suspect claims to have taken poison https://t.co/fgJtWSLTKk pic.twitter.com/DXLhJZmh3Y

— euronews (@euronews) November 29, 2017

Praljak's lawyer, Natasa Faveau-Ivanovic, was quoted by Reuters news agency as saying, "My client says he drank poison this morning."

The UN war crimes tribunal found that Praljak failed to make any attempt to prevent soldiers from rounding up Muslims in Prozor in the summer of 1993. He also failed to act on information that murders were being planned, as well as attacks on members of international organisations and property in East Mostar such as mosques.