The International Commission of Jurists provided the brief to police, which includes testimony from Sri Lankans who say they were attacked by government forces.
But the I-C-J denies reports that the brief names former Navy chief Thisara Samarasinghe, now Sri Lanka's High Commissioner to Australia.
The controversy comes ahead of the Sri Lankan President Mahinda Rajapakse's visit to Australia for CHOGM - the Commonwealth Heads of Government meeting - next week.
Reporter: Joanna McCarthy
Speakers: John Down, International Commission of Jurists; Admiral Thisara Samarasinghe, Sri Lankan High Commissioner to Australia; Lee Rhiannon, Australian Greens Senator; Australian MP Don Randall, deputy chair of the Sri Lanka Parliamentary Friendship Group
McCARTHY: The International Commission of Jurists says it originally compiled its dossier for use in an independent war crimes tribunal on Sri Lanka. It includes testimony from Sri Lankans who are now living in Australia, who allege they were attacked by government forces.
The ICJ's John Dowd says they've now handed the dossier to the Australian Federal Police.
DOWD: So that if they considered that a prosecution should be brought, they're in a better position to be able to do that.
McCARTHY: But he denies the ICJ is singling out the former navy chief Thisara Samarasinghe, now the High Commissioner to Australia.
DOWD: We're not commenting on anybody, other than the facts of the civil war and the war crimes. We're not naming anybody. That's a matter for the police, they have a job to do, we're not going to hinder them by nominating particular people.
MCCARTHY: The High Commissioner is the Sri Lankan navy's former eastern and then northern areas commander. He strongly denies allegations that any war crimes were committed by subordinates in his command.
SAMARASINGHE: I will totally reject such baseless and unsubstantiated allegations. I was Sri Lankan navy, never fired at civilians, they fired at terrorists when they were fired upon, and they the terrorists, is the group that fired at civilians. And during my command of the navy there was no conflict. The conflict was over when I took over the navy, but when I was in command of the north, as the area commander, was the final stage of conflict, was taking place in the east. However, I would always and very authentically say that the Sri Lankan navy, at any stage of the conflict, did NOT deliberately or otherwise, target civilians or fired at the civilians.
MCCARTHY: The final offensive against the Tamil Tigers ended in May 2009. It brought to a close a conflict that had lasted 26 years - but Amnesty International says ten to 20,000 civilians were killed in those final months. A United Nations advisory panel has found there is "credible allegations" that both sides committed war crimes, which the government strongly denies.
Australian Greens Senator Lee Rhiannon:
RHIANNON: The UN has reported up to 40,000 people died, there's growing momentum around the world, for a war crimes tribunal, and now, Australia, the foreign minister, Mr Kevin Rudd, should throw weight behind this call.
MCCARTHY: A spokeswoman for the Foreign Minister Kevin Rudd says the Australian Government has made no secret of its concerns about civilian casualties during the final stages of the war. She says Australia's view is that accountability and reconciliation will be a crucial part of long-term peace in Sri Lanka and Australia has made such views known to Sri Lanka.
But John Dowd says more needs to be done.
DOWD: I'm sure that Foreign minister Kevin Rudd has made those representations and I was already aware of that. But it's not enough to do it, directly, diplomatically. It's got to be Australia speaking out publicly on the matter. A communication of a diplomatic nature does not get the public aware of the issues and it doesn't let the rest of the international community, to raise the issue and bring pressure on the Sri Lankan government.
MCCARTHY: But supporters of the Sri Lankan government say human rights groups are just trying to embarass Colombo ahead of next week's meeting. Don Randall is a federal opposition member of parliament, and deputy chair of the Sri Lanka parliamentary friendship group.
RANDALL: It's designed to try and embarrass the Sri Lankan President when he's in Australia, in front of CHOGM, in front of an international audience. The timing's just too cute to be not recognised for what it is. And as I said, you have this group sorely on the world, who're endeavouring to and discredit a democratically-elected government, who's been through one of the most vicious civil wars. There're faults on all sides, I'm not suggesting that there're not any issues to be dealt with, but that's been dealt with internally, in Sri Lanka, by the Lessons Learnt and REconciliation Commission that the Sri Lankan government has set up, it's taking evidence. And can I say that it's interesting the human rights committee hasn't even made a submission to that Lessons Learnt and Reconciliation dody in Sri Lanka.