The United Nations failed miserably to protect hundreds of thousands of civilians caught up in the last months of Sri Lanka's civil war, says an internal inquiry.
According to the investigation's findings, which were obtained by the BBC, the organisation should in future be able "to meet a much higher standard in fulfilling its protection and humanitarian responsibilities".
Chief among the findings was criticism of the United Nations' decision to withdraw foreign and local staff from the war zone after September 2008 when the Sri Lankan authorities said they could no longer guarantee their safety.
The review also questions why the UN failed to publish mounting civilian casualty figures it obtained, and why - under pressure from the Sri Lankan Government - it did not make clear that a "large majority" of the civilian deaths were caused by Government forces.
Up to 10,000 civilians lost their lives in the first five months of 2009 as Government troops stepped up their operation to crush the last fighters of the once-powerful Liberation Tigers of Tamil Eelam (LTTE), a movement of militant Tamil separatists.
The UN later said there were convincing allegations both sides committed war crimes.
The Sri Lankan authorities did everything they could to ensure independent witnesses did not see what took place on the battlefields. The north was cut off by roadblocks and military checkpoints. Foreign journalists were kept far away from the fighting.