Hassan Nasrallah, the leader of Hezbollah, said on Thursday that "undisciplined members" of the group will be linked with the 2005 assassination of Rafiq al-Hariri, the former prime minister.
The UN-backed Special Tribunal for Lebanon is investigating al-Hariri's murder. Lebanese media reported earlier this week that it could issue its first round of indictments later this year.
In an interview published on Friday in the London-based Al-Hayat, al-Hariri said that the tribunal's findings would be in Lebanon's "national interest".
"I will look at the national interest, and the national interest is the truth," al-Hariri said. "If it wasn't so, why was the tribunal established?"
Hezbollah has been critical of the tribunal since it began its work last year. Nasrallah repeated the group's complaints on Thursday, calling the tribunal "biased" because it "does not look into the possibility that Israel is implicated".
Rafiq al-Hariri and 22 others were killed by a bombing on the Beirut seafront on February 14, 2005. The assassination sparked an international outcry and led to the withdrawal of Syrian troops from Lebanon.
The murder has been widely blamed on Syria, but Damascus has routinely denied involvement.