The report, which was earlier scheduled to be released on March 25 during the 28th session of the UN Human Rights Council, will now be out in September this year.
UN High Commissioner for Human Rights Zeid Ra'ad Al Hussein said it was a "difficult decision" to postpone the release of the report but added that given the changing context in Sri Lanka, there is possibility that important new information may emerge which will strengthen the report.
"This has been a difficult decision," Zeid said.
"There are good arguments for sticking to the original timetable, and there are also strong arguments for deferring the report’s consideration a bit longer, given the changing context in Sri Lanka, and the possibility that important new information may emerge which will strengthen the report," he said.
He sought to assure that the deferral was "for one time only", and guaranteed that the report would be published by September.
"There should be no misunderstanding," Zeid said.
In addition, the High Commissioner said he has received clear commitments from the new Government of Sri Lanka indicating it is prepared to cooperate with his office on a "whole range of important human rights issues -- which the previous government had absolutely refused to do -- and I need to engage with them to ensure those commitments translate into reality."
Zeid noted that the three experts appointed by his predecessor Navi Pillay to advise the investigation, had informed him that, in their unanimous view, a one-off temporary deferral would be the best option to allow space for the new government to show its willingness to cooperate on human rights issues.
"Taking all this into account, I have therefore decided, on balance, to request more time to allow for a stronger and more comprehensive report," he said.
"I want this report to have the maximum possible impact in ensuring a genuine and credible process of accountability and reconciliation in which the rights of victims to truth, justice and reparations are finally respected," he said.
Sri Lanka has appealed to the UN to delay the report so that the new government can carry out an internal probe even as it acknowledged that such violations did take place.
Lanka's new President Maithripala Sirisena took power last month after defeating Mahinda Rajapaksa who had vehemently resisted cooperation with the UN mandated probe.
Sri Lanka has been subject to three UNHRC resolutions in 2012, 2013 and 2014 over alleged rights abuses by government troops during the last phase of the three decade-long war with the LTTE in 2009.
In March last year, the 47-member UNHRC adopted a resolution which requested the Office of the High Commissioner to undertake a comprehensive investigation into alleged serious violations and abuses of human rights and related crimes by both parties in Sri Lanka during the period.
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