The United Nations’ human rights chief has recommended an international investigation into war crimes committed in Sri Lanka during the final stages of its Tamil separatist conflict, a report says.

The local Sunday Times newspaper in Sri Lanka said Navi Pillay has asked the UN Human Rights Council (UNHRC) to set up independent probe, saying Colombo “consistently failed to establish the truth” and ensure accountability for the atrocities, despite repeated calls.

“Establish an international inquiry mechanism to further investigate the alleged violations of international human rights and humanitarian law and monitor any domestic accountability process,” the Sunday Times quoted Pillay as saying.

The newspaper quoted from Pillay’s report to next month’s UNHRC sessions in Geneva, an advance copy of which had been given to Colombo for its observations.

It accused Sri Lanka of failing to probe rights abuses and continuing to violate democratic freedoms.

There was no immediate comment from the Sri Lankan foreign ministry, but Colombo has repeatedly said that its troops did not commit any war crimes.

However, it has asked for more time to ensure ethnic reconciliation between majority Sinhalese and minority ethnic Tamils.

Pillay’s recommendations noted fresh emerging evidence of what took place during the final stages of the ethnic war that ended in May 2009 with the crushing of the top leadership of the Liberation Tigers of Tamil Eelam (LTTE) in a no-holds-barred offensive.

The UN has previously alleged that up to 40,000 Tamil civilians may have been killed during the final months of fighting and blamed many of the atrocities on government forces, a charge Colombo vehemently denies.

“…National mechanisms have consistently failed to establish the truth and achieve justice (in Sri Lanka),” Pillay noted. “The High Commissioner (Pillay) believes this can no longer be explained as a function of time or technical capacity, but that it is fundamentally a question of political will.”

The United States, which leads international calls for war crimes investigations in Sri Lanka, has said it will move its third censure resolution against Colombo in as many years when the UNHRC holds its next session from early March.

A report released by the Public Interest Advocacy Centre in Australia earlier this month claimed that Sri Lankan soldiers committed the “vast majority” of crimes in a final government offensive against Tamil Tiger who fought for outright independence.

The UN has estimated that at least 100,000 people were killed in Sri Lanka’s Tamil separatist war between 1972 and 2009.