Sri Lanka's Ambassador to the UN in Geneva, Ravinatha Aryasinghe, said yesterday that Pillay has "no mandate to make such a claim". He insisted that his government had put in place "multiple mechanisms to address accountability."
"Sri Lanka needs to be encouraged and not impeded," Aryasinghe said.
Pillay yesterday called on Colombo to use the time left before she delivers a widely-anticipated report on the country to the UN Human Rights Council next March "to engage in a credible national process with tangible results, including the successful prosecution of individual perpetrators."
Pillay, who conducted a fact-finding trip to Sri Lanka last month, said she had received "little new information about the courts of inquiry appointed by the army and navy to further investigate the allegations of civilian casualties and summary executions" towards the end of the civil war.
The UN estimates that up to 100,000 people died during the conflict between 1972 and 2009, and rights campaigners claim 40,000 civilians were killed in the final military offencive in 2009 that crushed LTTE rebels.