UN leader Ban Ki-moon sent a report accusing Sri Lankan troops of killing tens of thousands of people in an offensive against Tamil separatists to the UN Human Rights Council, bringing an international inquiry one step closer.Ban has said that he alone cannot order an inquiry into the killings -- which the Sri Lankan government has strongly denied -- but that a forum such as the Human Rights Council could do so. UN spokesman Martin Nesirky said the report had been sent to the Human Rights Council and the UN High Commissioner for Human Rights, on Monday.A panel of experts named by Ban said in April that the Sri Lankan army killed most of the tens of thousands of civilian victims of a final offensive against Tamil separatists in 2009 but both sides may be guilty of war crimes. The panel\'s report -- angrily opposed by the Sri Lankan government -- painted a barbarous picture of the offensive on the Tamil enclave in the north of the island that ended a three-decade war with the Liberation Tigers of Tamil Eelam (LTTE). \"The Sri Lankan Government has been informed of the secretary general’s decision to share the report with the council and the high commissioner,\" said Nesirky. \"While the secretary general had given time to the government of Sri Lanka to respond to the report, the government has declined to do so, and instead has produced its own reports on the situation in the north of Sri Lanka, which are being forwarded along with the panel of experts report.\"The UN also said Thoraya Obaid, a former head of the UN Population Fund, would review the actions of the United Nations in Sri Lanka during the offensive after the panel also criticised UN decision-making.