A post-mortem examination on the body of Libya's ex-leader Col Muammar Gaddafi is expected to be carried out on Saturday in the city of Misrata. His burial has been delayed, with officials divided about what to do with the body. The UN and Col Gaddafi's family have called for a full investigation into the circumstances of his death. Video footage showed Col Gaddafi alive after his capture in Sirte on Thursday, and then dead a short time later. The US has called on Libya's new authorities to give a full account of Col Gaddafi's death in an "open and transparent manner". Libya's National Transitional Council (NTC) is expected to formally announce the liberation of the country during the weekend. Meanwhile, Nato says it will end its campaign in Libya by 31 October. The alliance's Secretary General, Anders Fogh Rasmussen, said that as the mission wound down, Nato "will make sure there are no attacks against civilians during the transition period". Nato's seven-month campaign of air strikes was carried out under a UN mandate authorising the use of force to protect civilians in Libya. Body in freezer Hundreds of Libyans have been queuing to get a glimpse of the body of Col Gaddafi in a meat storage room in Misrata. The BBC's Gabriel Gatehouse in the city says some - mostly women - craned their necks to see the body of his son Mutassim, who was also killed on Thursday. Officials, including acting Prime Minister Mahmoud Jibril, have also been to see the corpses. Oil Minister Ali Tarhouni told Reuters news agency Col Gaddafi would not be released for immediate burial. "I told them to keep it in the freezer for a few days... to make sure that everybody knows he is dead," he said. It is unclear whether the ex-leader will be buried in Misrata, in his hometown of Sirte, where he and his son were captured, or elsewhere. Officials from the NTC have said they will conduct a secret burial. There is some speculation that they might even try to bury him at sea, as happened with al-Qaeda leader Osama Bin Laden, to prevent any grave being turned into a shrine. 'Major concerns' Meanwhile, questions are mounting as to exactly what happened in Col Gaddafi's last moments following his capture. Mr Jibril said Col Gaddafi had been shot in the head in an exchange of fire between Gaddafi loyalists and NTC fighters in Sirte. Video footage suggests he was dragged through the streets. An NTC fighter told the BBC on Thursday that he found the former Libyan leader hiding in a drainage pipe and he had begged him not to shoot. Misrata's chief forensic doctor, Othman al-Zintani, told al-Arabiya TV that full autopsies would be carried out on the bodies of Col Gaddafi and his son. The post-mortems are scheduled to take place on Saturday and are expected to take several hours. Senior NTC member Mohammed Sayeh told the BBC he doubted that the colonel had been deliberately killed, but added: "Even if he was killed intentionally, I think he deserves this." In Washington, state department spokesman Mark Toner said the NTC "has already been working to determine the precise cause and circumstances of Gaddafi's death, and we obviously urge them to do so in an open and transparent manner as we move forward". But Russia's Foreign Minister Sergei Lavrov said the "way his death happened poses an entire number of questions". Mr Lavrov called for a full investigation, echoing a similar call by UN Human Rights Commissioner Navi Pillay. Her spokesman Rupert Colville told the BBC that the killing could have been illegal. "There are two videos out there, one showing him alive and one showing him dead and there are four or five different versions of what happened in between those two cell phone videos. That obviously raises very, very major concerns," he said. However, correspondents say few Libyans are worried about the manner of their former dictator's humiliating end. Celebrations continued late into the night across Libya. Col Gaddafi, who came to power in a coup in 1969, was toppled in August. He was making his last stand in Sirte alongside two of his sons, Mutassim and Saif al-Islam, according to reports. There are conflicting reports as to the whereabouts of Saif al-Islam, and Col Gaddafi's security chief - who are both at large.