BENGHAZI (Reuters/AFP) - Libya declared the liberation of the nation on Sunday after 42 years of one-man rule by Muammar Gaddafi came to an end with his capture and death last week, setting the North African state on course for a transition toward democracy. "We declare to the whole world that we have liberated our beloved country, with its cities, villages, hill-tops, mountains, deserts and skies," said an official who opened the ceremony in Benghazi, the place where the uprising erupted in February and which has been the headquarters for the National Transitional Council. Salah el Ghazal, another official who addressed the tens of thousands of people gathered for the celebrations, said that Libya was blessed with Mustafa Abdel Jalil, the head of the NTC. "God has blessed us with the Mustafa Abdel Jalil, who deserves to be the man of the hour," said Ghazal, who is a local official of the NTC. Crowds listening to Libyan music and waving the tri-colour flag cheered. Ghazal paid tributes to all those who died, and referred to the "humiliating" death of Gaddafi. "This is the humiliating end that God wanted to set as example for anyone who practices the worst forms of injustice .. against their people," Ghazal said. Meanwhile, an autopsy has been carried out on the body of Gaddafi, who was controversially killed after being captured alive by new regime fighters, an official said. "The autopsy was carried out this (Sunday) morning," Misrata military council spokesman Fathi al-Bashaagha told AFP. "We had not planned to do an autopsy but Tripoli requested that we make sure things are done correctly," he said. The judge in charge of organising the autopsy confirmed that the body of Gaddafi, 69, had been examined, adding he was waiting for a report on the causes of death. "The autopsy was completed at 10:00 am (0800 GMT) but the report has not been written yet so I haven't been informed yet of the causes of death," said Abdel Salam Baayu. Since he was killed on Thursday trying to flee his hometown of Sirte, Gaddafi's body has been held in a refrigerated chamber outside Misrata, drawing large crowds wanting to view the remains of the despot who ruled Libya with an iron fist for decades. An autopsy was also carried out, on Saturday, on the body of Mutassim Gaddafi, a son of the former leader, who was likewise captured in Sirte on Thursday and displayed next to his father. The National Transitional Council, dismissing charges he was executed, insists the fugitive former leader was caught in crossfire between new and old regime fighters. The new Libyan authorities originally said Libya's so-called "Guide" would be buried in a secret place to prevent any kind of pilgrimage to his grave in the future. But on Sunday they announced that Gaddafi's remains would be returned to his extended family. "The decision has been taken to hand him over to his extended family, because none of his immediate family are present at this moment," senior government advisor Ahmed Jibril told AFP. "The NTC are in consultation with his family. It is for his family to decide where Gaddafi will be buried, in consultation with the NTC," he added. Jibril, who is an advisor to the new regime's interim premier Mahmud Jibril, declined to say when the transfer would take place. Gaddafi's immediate family are either dead, in exile or unaccounted for. Gaddafis widow Safia and three of their children - their daughter Aisha and sons Hannibal and Mohammed - fled Libya in August and found shelter in Algeria. Another son, Saadi, escaped to Niger on September 11. Three of Gaddafi's children have been killed since a popular revolt erupted in February: Mutassim, who was killed on Thursday in Sirte, Seif al-Arab, struck during a Nato raid in April, and Khamis, who died in combat in August. While, Libyan revolutionary fighters are surrounding an area where fugitive son of Gaddafi, Saif al-Islam, is believed to have taken refuge, a military commander of the NTC said. The commander, Abdel Majid Mlegta, told Reuters fighters were deploying around a place south of the town of Bani Walid where they believed Saif al-Islam was hiding following his flight from his father's hometown of Sirte on Thursday. Mlegta said Gaddafi's Niger-based security chief Abdullah al-Senussi had been in contact with Saif al-Islam to try to help him escape and flee to the Sahelian country "but our brigades are encircling this area south of Bani Walid." Safia was quoted by Syria-based Arrai television on Friday calling for a UN investigation into the circumstances of her husband's death. US Secretary of State Hillary Clinton also said on Sunday the United States supports a possible UN investigation into the death of Libyan leader Gaddafi. "I would strongly support both a UN investigation that has been called for and the investigation that the Transitional National Council said they will conduct," Clinton told the NBC programme "Meet the Press," referring to Libya's interim rulers. "You know, I think it's important that this new government, this effort to have a democratic Libya, start with the rule of law, start with accountability," she said. UN Human Rights Commissioner Navi Pillay has called for an investigation into the killing. There is growing international disquiet about the chaotic scenes surrounding Gaddafi's apparent summary execution following the fall of his hometown of Sirte Thursday. Libya's outgoing prime minister said on Sunday a bullet that hit Gaddafi's head may have been fired by one of his own guards during a shootout with government forces in his hometown of Sirte. "So I view the investigation on its own merits as important but also as part of a process that will give Libya the best possible chance to navigate towards a stable, secure, democratic future," Clinton said.