Prime Minister Julia Gillard raised the accusations in bilateral talks with President Mahendra Rajapakse in Perth ahead of the Commonwealth Heads of Government Meeting (CHOGM), which opens Friday.
Speaking ahead of the meeting, Gillard told reporters: "I have been clear about Australia's position in relation to allegations of human rights abuse in Sri Lanka.
We believe that this is a serious question.
"
As a lawyer's group said it had new evidence showing Sri Lankan troops committed war crimes in 2009, Foreign Minister Kevin Rudd said the UN Human Rights Council must examine whether atrocities occurred.
He also said Sri Lanka, which strongly denies any wrongdoing by government forces, should investigate the claims as part of its own Reconciliation Commission report, due out next month.
"It is of fundamental importance that the upcoming Reconciliation Commission report deal with various questions which have now been raised in the UN report on allegations of human rights abuses in S