Bhutto was killed in a gun and suicide bomb attack after an election rally in the city of Rawalpindi on Dec 27, 2007, after she returned to Pakistan from eight years in self-imposed exile.
"Bhutto's assassination could have been prevented," said the report by a three-member panel headed by Chile's UN ambassador Heraldo Munoz.
The report slammed the then Musharraf government for both the failure to protect Bhutto and later for the deliberate "failure" to investigate the murder.
The investigators stressed that besides passing on messages of the serious threats to Bhutto, no proactive measures were taken to neutralise the danger by the authorities.
"While she died when a 15-and-a-half-year-old suicide bomber detonated his explosives near her vehicle, no one believes that this boy acted alone," Munoz said.
The report did not name any suspected culprits but urged Pakistan to conduct a proper investigation.
It was presented on Thursday, Apr 15 to UN Secretary-General Ban Ki-moon.
The release of the report was delayed for just over two weeks because of a request by President Asif Ali Zardari, Bhutto's widower, to allow the commission to hear evidence from three unidentified heads of state.