U.N. officials say the Secretary-General will soon refer a report about alleged war crimes in Sri Lanka's recent civil war to the global body's Human Rights Council, a move that could lead to an international investigation of the conflict.

The officials said Monday Ban Ki-moon is likely to send the report – published in April – to the Geneva-based Human Rights Council in the coming days. Written by a panel of UN-appointed experts, the report cites “credible” evidence of Sri Lankan troops and Tamil rebels committing human rights violations, including possible war crimes, in the final months of the war that ended with a rebel defeat in 2009.

The panel estimated that thousands of Tamil civilians were killed by the end of the 25-year conflict. It called for an international investigation of the allegations.

The Human Rights Council must agree to debate the report before it can give Mr. Ban a mandate to launch such an investigation.

Sri Lanka has rejected the report's findings and says it opposes an outside investigation. The Sri Lankan government has appointed its own national commission to investigate the civil war and is expected to publish its findings in mid-November.

U.S. Assistant Secretary of State Robert Blake discussed the status of Sri Lanka's investigation with Sri Lankan President Mahinda Rajapaksa in the capital, Colombo, on Monday. Blake also held talks with a leader of Sri Lanka's major Tamil party, the Tamil National Alliance.