Hezbollah denies any involvement in 2005 bombing that killed Hariri and 22 others. [Getty Images]
The prosecutor of a UN-backed tribunal investigating the assassination of Rafik Hariri, the former Lebanese prime minister, has filed a new indictment.
The new charges include "substantive new elements" that have only recently come to light, the Dutch-based tribunal said in a statement. The contents of the original indictment, filed in January, remain secret.
The prosecution's office refused to elaborate on the new details that prompted the update citing confidentiality.
Hariri was killed along with 22 others by a truck bomb on Beirut's Mediterranean seafront on February 14, 2005.
The new indictment is expected to further delay a judge's decision on whether to confirm the indictment and issue arrest warrants for suspects.
The tribunal issued a statement saying the "large volume of supporting material" must be carefully scrutinised by Belgian judge Daniel Fransen, who will decide whether to confirm or dismiss the indictment. He also has the option of rejecting some of the charges and confirming others.
Canadian prosecutor Daniel Bellemare submitted his first indictment on January 17 and expanded it for the first time on March 11. He has not ruled out further changes or new indictments.
"The amendment of an indictment or the filing of new indictments is and will continue to be guided solely by the evidence uncovered by the ongoing investigation," Bellemare said in a statement.
Members of Hezbollah are expected to be named in the indictment. Hezbollah denies any involvement in Hariri's slaying, and its leader, Sheik Hassan Nasrallah, has said his group would "cut off the hand" of anyone who tries to arrest any of its members.
Unlike other international courts, the Hariri tribunal can hold trials in absentia if suspects cannot be arrested.
Hezbollah forced the collapse of Lebanon's Western-backed government led by Saad Hariri -- son of the slain former prime minister - in January in a dispute over the tribunal.