A proposal to appoint a Commonwealth human rights commissioner to steer a more proactive rights agenda looks set to test a leaders' summit this week, with host Australia backing the plan but India and South Africa reported to oppose it.

Sri Lanka also rejects outside interference in its human rights issues, which are set to divide the summit starting on Friday. U.N. and human rights groups call for an independent inquiry into allegations of war crimes during its war with Tamil Tiger rebels which ended in 2009.

A confidential Commonwealth report to the leaders recommends reforms to avoid a slide into irrelevance, including that the group act more decisively to uphold human rights among its 54 member nations.

Australia's position has always been in support of an enhanced engagement on democracy and human rights, which is contained in that recommendation, Australian Foreign Minister Kevin Rudd said on Wednesday.

But I believe we have to be very realistic about the timetable, said Rudd, hinting at divisions.

Local media said India and South Africa were opposing the appointment of an independent human rights commissioner.

The Commonwealth includes Britain, its former colonies, and a population of two billion people. Five Commonwealth countries, Britain, Australia, Canada, India and South Africa, are members of the G20, but many member states from Africa, the Pacific and Caribbean are amongst the world's poorest.

Rich members, such as Australia, Britain and Canada want a stronger focus on human rights. Canada has criticised Sri Lanka over its rights record and has threatened to boycott the leaders' summit in 2013 in Colombo.

Sri Lanka is due to hand down a human rights report in November, but rights groups believe it will be flawed because they say there is no effective witness protection scheme.

The respect for fundamental human rights is one of the core values of the Commonwealth and leaders have repeatedly reaffirmed their commitment to the respect of human rights, said Commonwealth Secretary General Kamalesh Sharma.

We have offered our support to Sri Lanka in the past and remain available to assist if the Sri Lankan government wish us, he said, citing the Commonwealth's experience in reconciliation, rights, and political power sharing.

The Commonwealth, which already has the power to adopt sanctions against member states that fail its democracy test, suspended Fiji in 2009 after a military coup.

No Commonwealth country looks forward to the prospect of being suspended or expelled from the Commonwealth, said Rudd in defending the Commonwealth's human rights actions.

But a report by a 10-member Eminent Persons Group, commissioned by Commonwealth leaders in 2009, recommends the organisation become proactive in its support of human rights.

The report said there was growing criticism that the organisation's watchdog, the Commonwealth Ministerial Action Group (CMAG), had only responded when there has been a coup d'etat or a military seizure of power in a member state.

CMAG should draw up specific steps, such as the violation of the opposition's rights, that would trigger intervention with a member state to take corrective action, it said.

The report also proposed the Commonwealth beef up its role in observing elections, with observers arriving two months before an election, instead of two weeks before as they do now.

Pre-emptive diplomacy is alive in those discussions within CMAG..., said Rudd. There is potency to the argument that there is a danger in the Commonwealth being simply reactive rather than proactive.

Once a military coup occurs, then the one blunt instrument available to the Commonwealth is one of suspension or expulsion. On the pre-emptive diplomacy side there may be other means that we can deploy.

(Reporting by Michael Perry; Editing by Ron Popeski)