The U.N.-backed Lebanon tribunal's prosecutor on Friday expanded the scope of his indictment over the 2005 killing of statesman Rafik al-Hariri, delaying the review process by months.

The Lebanon tribunal, the world's first international court with jurisdiction over the crime of terrorism, was set up to try those accused over the 2005 bombing that killed Lebanese ex-prime minister Hariri and 22 others.

Open gallery view Former Lebanese Prime Minister Rafik Hariri and Hezbollah leader Hassan Nasrallah, May 25, 2001. Credit: AP

The prosecutor's original indictment filed in January, the contents of which are still secret, set off a political crisis in Lebanon, where the militant Shi'ite group Hezbollah and its allies toppled the government of Hariri's son, Saad al-Hariri.

Lebanese officials and Western diplomats expect the court to accuse Hezbollah members of involvement in the assassination, a prospect Lebanese politicians fear could fuel further tensions.

Hezbollah, a powerful Shiite militia, has said it believes some of its members may be named, and has warned the case could touch off renewed bloodshed in Lebanon.

Prosecutor Daniel Bellemare said in a statement he had expanded the scope of his original indictment after collecting and analyzing further evidence. All documents would remain confidential, he said.

The prosecutors' office declined to comment when asked if the expanded indictment meant more people were accused or more criminal acts were detailed, or both.

"The initial indictment was accompanied by thousands of pages of supporting material and as the prosecutor made clear in his statement today this 'amendment expands on the scope of the indictment filed on 17 January 2011'," a spokesman for the Special Tribunal for Lebanon said in separate statement.

"We are now talking about months rather than weeks for the indictment review process to be completed."

