moments before his death. An anonymous U.S. official subsequently described their policy in hindsight as "lead[ing] from behind". Because Libyan rebels had consistently told American government officials that they did not want overt foreign military assistance in toppling Gaddafi, covert military assistance was used (including arms shipments to the opposition). The plan following Gaddafi's death was to immediately begin flowing humanitarian assistance to eastern Libya and later western Libya, as the symbolism would be critically important. U.S. sources stressed it as important that they would "not allow Turkey, Italy and others to steal a march on it". Concurrent capture or death of relatives and associates National Transitional Council officials also announced that one of Gaddafi's sons, Mutassim, once the Libyan national security advisor, was killed in Sirte the same day. A video later surfaced showing Mutassim's body lying in an ambulance. A video aired on Al Arrai television showed Mutassim alive and talking to his captors. The circumstances of his death are unclear. Another son, Saif al-Islam Gaddafi, was captured almost a month after his father's death, while trying to flee to Nigeria. Footage had emerged earlier on 20 October 2011 showing the body of Gaddafi's defence minister, Yunis Jabr. Abdul Hakim Al Jalil, the commander of the NTC's 11th Brigade, stated that former Gaddafi spokesman Moussa Ibrahim had been captured near Sirte. Reports indicate that Ahmed Ibrahim, one of Gaddafi's cousins, was also captured. Subsequent events Calls for investigation Numerous organizations, including the United Nations and the U.S. and UK governments, have called for an investigation of the exact circumstances of Gaddafi's death, amid controversy that it was an extrajudicial killing and a war crime. The UN High Commissioner for Human Rights, Navi Pillay, had said there should be a full investigation. The UN Human Rights Office spokesperson said that he expects the UN commission already investigating potential human rights abuse in Libya would look into the case. Waheed Burshan, a member of the NTC, said that an investigation should happen. On 24 October 2011, the NTC announced that it had ordered an investigation in response to the international calls and that it would prosecute the killers if the investigation showed he died after his capture. Almost a year later, on 17 October 2012, new evidence was revealed by Human Rights Watch showing that mass killings occurred at the site of Gaddafi's death. Regional ramifications In its immediate aftermath,