Despite claims by Libya's interim government that dictator Moammar Gadhafi was killed in crossfire after revolutionary fighters captured him Thursday, a Libyan rebel has confessed on camera to the killing.

Immediately following Gadhafi's death, videos began to surface showing him being held up by rebels, raising the suspicion he was executed, The Daily Mail reported.

The rebel, who identified himself as Senad el Sadik el Ureybi, said: We grabbed him, I hit him in the face. Some fighters wanted to take him away and that's when I shot him twice, in the head and in the chest.

El Ureybi added that it took Gadhafi a half an hour to die, and that he killed Gadhafi it because he didn't like the idea of him being caught alive.

Attempting to prove the video's authenticity, the fighter flaunted what appears to be Gadhafi's bloodstained shirt, before also showing a ring he says he pulled off of Gadhafi's finger.

The claims have not yet been confirmed.

On Sunday, an autopsy confirmed that Gadhafi died from a gunshot wound to the head, Libya's chief pathologist, Dr. Othman al-Zintani, said, though not disclosing whether the findings revealed if the gunshot wound was from close-range or in crossfire. That question has the United Nations and human rights groups calling for an investigation into the last moments of the Libyan dictator's life.

U.S. Secretary of State Hillary Rodham Clinton and Britain's new defense secretary, Philip Hammond, said a full investigation is necessary.

Clinton told NBC's Meet the Press that she backs a proposal that the UN investigate Gadhafi's death and that Libya's National Transitional Council also look into the circumstances.

Hammond said the Libyan revolutionaries' image has been a little bit stained by the Libyan dictators death, adding that the new government will want to get to the bottom of it in a way that rebuilds and cleanses that reputation.

It's certainly not the way we do things, Hammond told BBC television. We would have liked to see Col. Gadhafi going on trial to answer for his misdeeds.

The autopsy was performed in front of officials from the prosecutor's office at a Misrata hospital, Zentani said, adding that the report will go to the attorney general's office before being released to the public.

On Friday, Gadhafi's family issued a statement, calling on the United Nations and Amnesty International to push Libya's leadership to hand over the bodies of the martyrs of their tribe so they can be buried according to Islamic rites, a pro-Gadhafi TV station reported.

Gadhafi's death Thursday brought an end to an eight-month war backed by NATO, after revolutionary fighters overran his hometown of Sirte, 280 miles east of Tripoli, and found him hiding in a drainage ditch.

Leaders of Libya's interim government have said Gadhafi was killed in crossfire after fighters captured him Thursday, CNN said.

Peter Bouckaert, Human Rights Watch's emergencies doctor, counters that claim, saying fighting had ended when Gadhafi was cornered in a drainage ditch.

When he left the area, he was very much alive, Bouckaert said. There's no reason why he should have been subjected to this kind of mob justice.

Autopsies were also performed on Gadhafi's son, Mutassim, and former defense minister Abu Baker Yunis. The three bodies will likely return to a cold storage unit at a Misrata meat market for public viewing, Zentani said.