Last year, the Special Tribunal for Lebanon in the Netherlands found Ayyash guilty in absentia and handed him five life terms over the killing of Hariri in a suicide bombing in Beirut in 2005.
Ayyash, 57, remains in hiding while Hezbollah Secretary-General Hassan Nasrallah refuses to hand him over or to recognise the court’s authority.
Last January, Ayyash’s defence lawyers appealed the verdict, but a majority of the court’s judges on Tuesday decided to reject the appeal.
The court said in a statement that “the legal framework for in absentia proceedings at the STL does not contemplate a defense appeal in absentia,”, adding that “counsel for Mr. Ayyash have not been appointed nor accepted by Mr. Ayyash, who absconded and has not been found. An arrest warrant against Mr. Ayyash is outstanding.”
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The court said Ayyash maintains “the right to appeal the judgments if he appears, or request a retrial” in accordance with international human rights standards.
Hariri was killed along with 22 other people in a huge truck bombing that also injured 226 others.
Ayyash faces a separate case at the tribunal for three attacks on politicians in Lebanon that is due to open in June.
In March, the United States offered a reward of $10 million for information leading to the location or identification of Ayyash.