BEIRUT: The U.N.-backed court probing the 2005 assassination of statesman Rafik Hariri is not investigating “false witnesses” in the case, the Special Tribunal for Lebanon said Wednesday.

In a question-and-answer session with journalists and members of the public on Twitter, STL Registrar Herman von Hebel said that since no allegedly false testimonies had been given to the court, the issue would remain a matter for an initial United Nations investigation.

“For the STL, there are no false witnesses since there have been no witnesses testifying in the courtroom,” von Hebel said on the court’s official Twitter feed. “In case of a false witness before the court, the judges can hold them in contempt of court. Any issues relating to individuals allegedly providing false information to the [U.N. International Independent Investigation Committee (UNIIIC)] is a matter for Lebanon and the U.N.”

Among the charges leveled against the court by detractors is that much of the evidence gathered by the UNIIIC – the initial investigation into Hariri’s assassination – is based on false testimonies. In particular, two self-proclaimed former Syrian intelligence officers, Mohammad Zuheir Siddiq and Husam Taher Husam, provided information to the investigation that has since been discredited.

Both alleged high-level Syrian involvement in Hariri’s killing, and have been living under protection for several years. In 2009, shortly after the STL’s foundation, the Office of Prosecutor Daniel Bellemare declared that Husam and Siddiq were no longer of interest to the court.

Senior March 8 figures have called for the STL to investigate the issue of false witnesses.

Von Hebel also commented on a series of information leaks that have hampered the investigation into the 2005 bombing and stoked controversy surrounding the court.

“We do recognize that there have been leaks. This was primarily from the UNIIIC period. Stories about leaks from the STL itself have been greatly exaggerated,” Hebel said. “At any rate, any such stories won’t impact judicial proceedings as the judges will only consider evidence presented in court.”

The court has been subjected to accusations of politicization since its inception, in spite of several public attempts by senior STL figures to defend their integrity and impartiality.

Von Hebel was asked whether he knew that “most” Lebanese did not have faith in the tribunal. In response, he tweeted: “It’s too early to pass judgment on STL. The first trial has yet to begin and we should be judged by the fairness of our trials.”

Reports have emerged that STL Prosecutor Daniel Bellemare – who in June accused four Hezbollah members of Hariri’s assassination – is finalizing an indictment in the case of Marwan Hamadeh, the former telecommunications minister who survived an attempt on his life in October 2004. In addition, the STL is known to be probing the files of slain Communist Party leader George Hawi and former Deputy Prime Minister Elias Murr.

Von Hebel said that the reports of an imminent indictment in the cases were premature. “As you know there have been 3 connected cases on which we’ve established our jurisdiction. The prosecution continues to examine the cases in order to determine whether there is a basis to submit an indictment to the Pre Trial Judge,” he said.

Lebanon finally agreed last week to provide its share of 2011 funding – equivalent to over $30 million – to the court in accordance with U.N. Security Council Resolution 1757, which is due for renewal in March 2012.

Von Hebel said that while STL President Sir David Baragwanath had recommended that the court’s mandate be renewed, the decision rested outside the tribunal’s control.

“The president of STL recommended an extension of the mandate to the U.N. secretary-general,” Von Hebel said.

“The [secretary-general] will consult the government of Lebanon and the Security Council. It is finally for the [secretary-general] to decide on the extension.”