Australia has voiced its opposition to an international investigation into alleged war crimes in Sri Lanka saying it is not convinced that the UN backed inquiry is "the best way forward".

The United Nations Human Rights Council passed a resolution on Thursday to launch an independent investigation into alleged atrocities in Sri Lanka, despite fierce opposition and allegations of bias from Sri Lankan officials.

Foreign Affairs Minister Julie Bishop opposes a UN resolution to condust an independent war crimes investigation in Sri Lanka. Credit:Alex Ellinghausen

Australia is not one of the 47 voting members of the council but could have co-sponsored the resolution if it backed the inquiry.

Twenty-three countries voted for the bill and 12 against and there were 12 abstentions.