U.N.-backed investigators have found that members of Hezbollah were behind the assassination in 2005 of Lebanese prime minister Rafik al-Hariri, Canadian public broadcaster CBC News has reported citing inquiry sources and documents.
It said evidence gathered by Lebanese police and later by UN-backed investigators "points overwhelmingly to the fact that the assassins were from Hezbollah."
Hezbollah, which is part of a unity government led by Hariri's son Saad has repeatedly denied any involvement in the killing. Its leader Sayyed Hassan Nasrallah said this month he will not allow the arrest of any of the group's members.
Hezbollah said on Monday it had no comment on the CBC News report. U.N spokesman Farhan Haq said the U.N. was aware of the report but was not commenting for now.
Hezbollah and Western diplomats say that an expected indictment against members of the group could come late this year or early next. Lebanese politicians fear a crisis, and possible relapse into violence, if that proves to be the case.
CBC News said on Sunday it had obtained mobile telephone and other telecommunications evidence which is at the core of the case.
It said that in 2007 the investigators asked a British firm to analyze telephone calls made in Lebanon in 2005.
"What the British analyst showed them (the U.N. investigators) was nothing less than the hit squad that had carried out the murder, or at least the phones they had been carrying at the time," CBC News said.
Lebanon had charged two employees at state-run mobile phone firm Alfa with spying for Israel in the past few months. They were arrested as part of a wider espionage investigation which lead to more than 50 arrests since April last year.
The arrests prompted debate on how deeply Israel had infiltrated Lebanon's telecoms and security sectors.
Hezbollah suggested Israel could have used telecom agents to manipulate evidence such as telephone records to implicate the group in Hariri's killing.
Hezbollah, which fought a war with Israel in 2006, has accused the tribunal of being an Israeli tool and said its investigators are sending information to Israel.
The investigation had first implicated Syrian and Lebanese officials, although it later held back from giving details of its findings. Saad Hariri had blamed Syria for killing his father but later said he was wrong to accuse Syria and that the charge was politically motivated.
Hariri's assassination plunged Lebanon into its worst crisis since the 1975-90 civil war. Sunni-Shi'ite tensions threatened to boil over into a civil war.
The CBC News report is close to one published by German magazine Der Spiegel in 2009 in which it cited information it had obtained saying that investigators believed Hezbollah was behind Hariri's killing.
The German magazine also said Lebanese investigators had found a link between eight cell phones used in the area at the time of the attack and a network of 20 other phones believed to belong to Hezbollah's "operative arm."