The commander of forces who captured Muammar Gaddafi has given details of the Libyan ex-leader's last moments.
Omran al-Oweib told the BBC that the injured colonel was dragged from a drainage pipe where he was hiding in Sirte, took 10 steps and collapsed amid gunfire on Thursday.
He said it was impossible to tell who had fired the fatal bullet.
Meanwhile confusion has emerged over whether a full post-mortem had been performed on Col Gaddafi.
His body - and that of his son Mutassim, who was also killed on Thursday - have been placed in a meat storage facility in the city of Misrata.
The foreign affairs spokesman of Libya's National Transitional Council (NTC), Ahmed Gebreel, told the BBC the post-mortem was carried out on Saturday.
However a senior health official within the NTC, Nagy Barakat, said there was no need for such an examination as the cause of death had emerged from a pathologist's report.
In an exclusive BBC interview, Mr Oweib said: "I didn't see who killed, which weapon killed Gaddafi." He added that some of his fighters had wanted to shoot the colonel, but that he had sought to keep him alive.
After Col Gaddafi collapsed, Mr Oweib said, he drove him to a field hospital where he was pronounced dead. "I tried to save his life but I couldn't," the commander said.
Questions have been mounting about the death. Video footage suggests he was dragged through the streets.
The US has called on officials to give an account in an "open and transparent manner". 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.
Acting Prime Minister Mahmoud Jibril told the BBC: "At the personal level I wish [Col Gaddafi] was alive. I want to know why he did this to the Libyan people. I wish I were his prosecutor in his trial."
Mr Jibril added that it would be "absolutely OK" to carry out a full investigation under international supervision, as long as Islamic burial rules were respected.
Correspondents say few Libyans are worried about the manner of their former dictator's humiliating end, which has been celebrated across the country.
The burial has been delayed, amid uncertainty about what to do with the remains.
It is unclear whether the ex-leader will be buried in Misrata, in his hometown of Sirte, or elsewhere.
Officials from the NTC have said they want a secret burial to prevent any grave being turned into a shrine.
Libya's is expected to formally announce the liberation of the country during the weekend.
The first elections should take place by next June, Libya's acting prime minister has said.
"According to what we call the constitutional declaration, the first election after the liberation of the country... should be within a period of eight months maximum," Mahmoud Jibril told a conference in Jordan.
"The national congress of Libya... is entitled with two tasks, the first one to draft a constitution over which we'll have a referendum and the second task is to form the interim government which should last until the first presidential elections are held."
Nato says it will end its campaign in Libya by 31 October.
The alliance's seven-month campaign of air strikes was carried out under a UN mandate authorising the use of force to protect civilians.
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.