In an interview with the 'Ceylon Today' newspaper in Colombo, Erik Solheim said, "I will stand witness before any recognised international tribunal if I am asked to do so".
Solheim, 59, was Norway's peace envoy from late 2000 until 2004, the high point of his role being when the LTTE and the government agreed on a peace pact on February 22, 2002. However, Sri Lankan nationalist groups accused Solheim and the Norwegians of being biased towards the LTTE.
Solheim says in his interview that top LTTE leaders were in touch with him on May 17, 2009 wanting to surrender to troops as the military was nearing victory.
"We told them it was too late for us to arrange anything and advised them about raising a white flag. On May 18 (when government troops declared victory), we were informed that they were killed".
He says he knew that Sri Lanka might face a rights probe, "Yes I knew what was going to come about. That was clear from the very beginning. There were too many innocent people who died in the war and that was at a tremendous cost".
Solheim's comments have come as the UN Human Rights Council is soon expected to announce its panel to probe allegations of rights abuses against Sri Lanka during the final stages of the 30-year civil war in 2009 when around 40,000 people are alleged to have been killed, a charge Colombo has denied.