The United Nations has decided to delay publication of its report on Sri Lankan war crimes. The findings were due to be produced next month. Instead the UN has agreed to delay release until September during which time investigators will gather more evidence, this time with the cooperation of the Sri Lankan government. Until his defeat last month, the previous president, Mahinda Rajapaksa had blocked UN inquiry teams. Even though there is strong evidence that in this brutal 26-year civil war, the Tamil Tiger rebels committed terrible atrocities, against their own people as well as the island's Singhalese majority, Rajapaksa opposed the UN probe from the start. This enhanced the suspicion that in the days following the defeat of the Tamil Tigers in their last redoubt on the Jaffna peninsula serious war crimes were committed. There were claims that rebel officers were summarily executed along with many of their subordinates. There were also allegations of rape and looting. What was clear, because international non-government organizations saw it, was that the entire Tamil population in the newly-recaptured areas was transported to camps. Rajapaksa insisted that the measure had been taken so that the inmates could be screened and former rebels lurking among the civilians could be identified. However, reports of regular abuse and the occasional outright murder caused outside access to the camps to be shut off. Though he dressed up his refusal to work with the UN as an issue of national sovereignty, Rajapaksa's stonewalling only served to boost suspicions that his administration had something to hide. The inquiry that he launched himself into war crimes was generally dismissed as a farce. Sri Lanka's new president Maithripala Sirisena asked the UN to hold off on publication of its war crimes report. He invited the investigators to come and take the evidence that they had previously been unable to obtain. That this is going to happen is a sensible decision by the international body. Whatever its findings, had the report been published next month, it could have been dismissed as flawed simply because the probe had not been given access to all the evidence. Rajapaksa's people would also have dismissed it as being prejudiced, inspired by the former president's insistence that the UN had no business to be investigating crimes allegedly committed on Sri Lanka's sovereign territory. On the face of it, the new September publication date seems a little optimistic. The final part of this investigation should take as long as it needs. To rush it would simply undermine its credibility. And then, when the report is finally published, will come the big questions. If evidence is found against individuals, are there to be prosecutions? If for instance Rajapaksa were found to have ordered war crimes, would he, along with the soldiers who carried out his instructions, be subject to trial in the International Criminal Court? Would such prosecutions be possible while some former Tamil Tiger leaders continue to live in exile? Should these individuals, if accused of war crimes, also be extradited to the Hague? Or is there a case, in the cause of Sri Lanka's political stability, for letting the UN report be the climax of this horrible war? These will be tough questions for President Sirisena. But for the moment he and the UN are absolutely right to reopen the war crimes probe to gather more evidence.