The report did not directly blame Syria for the assassination of Mr Hariri, an opponent of the Syrian presence in Lebanon, but said Damascus was behind the political tension and weak security that led to his death with 17 other people in a huge explosion on February 14.
"Clearly, Mr Hariri's assassination took place on the backdrop of his power struggle with Syria, regardless of who carried out the assassination and with what aim," the report said. The investigation was launched to help get to the bottom of Mr Hariri's killing.
Opposition leaders and foreign officials had feared he was killed for opposing pro-Syrian President Emile Lahoud, who was allowed to stay in office for another term after Parliament rewrote the constitution with Syria's approval.
Mr Hariri had also supported Security Council Resolution 1559, which demanded Syria withdraw its forces from Lebanon. It also said the council hoped Lebanon's upcoming elections would be free of foreign influence a reference to Syria, which has held enormous political influence in Lebanon since its troops entered the country in 1976. While the report accuses Syria of creating the conditions for
Mr Hariri's death, it reserves withering criticism for Lebanese authorities who handled the case.
The report says there was a "distinct lack of commitment" by the authorities to investigate the crime, and the probe was not carried out "in accordance with acceptable international standards." It detailed a host of flaws, including the disappearance of crucial evidence and tampering with the scene of the blast that killed Mr Hariri and at least 17 others. Parts of a pickup truck were brought to the scene, placed in the crater and photographed as evidence, it said.
The report alleged investigative judges had no control over the probe and even faulted police for not turning off a water main that flooded the blast crater and washed away vital evidence.
Studying the aftermath of the bombing, Deputy Commissioner Fitzgerald's team also cast serious doubts on the legitimacy of a suspect in the bombing, a Palestinian named Ahmed Abu Adas, and a group that claimed responsibility, the little-known Support and Jihad in Syria and Lebanon. He also faulted Syria for interfering in the governing of Lebanon "in a heavy-handed and inflexible manner." Investigators also received testimony that Syrian President Bashar Assad had threatened Mr Hariri and opposition figure Walid Jumblatt with physical harm.
Syria's UN Ambassador Fayssal Mekdad rejected the report, saying it contained "too much rhetoric."