Still smarting over a Senate Committee gruelling over its tobacco investments, the Future Fund - the largest fund in Australia - is being accused of insufficient transparency over climate-change risk mitigation within its portfolio.

A FOI search two years ago revealed that despite investor warnings of particular risks to long-term investors like the Future Fund, it had not once mentioned climate-change in any of its Board meetings.

Despite the more recent development of Australia's own carbon pricing scheme, the Future Fund is accused of not giving the issue sufficient oxygen or providing stakeholders with clarity about its strategies to protect its portfolio.

In a letter to the Asset Owners Disclosure Project, the $75 billion fund claimed it suffered "resource constraints."

Asset Owners Disclosure Project (AODP) Chair Dr John Hewson and former leader of the Liberal Party said: "It is quite extra-ordinary that Australia's largest fund which will have to supply pension liabilities over the long-term has decided not to come clean over its climate position."

"While investors all over the world continue to build understanding of how to protect themselves from the market and physical impacts of climate change, the Future Fund thinks it is immune. It needs to come clean."

It's understood that the former head of the Future Fund David Murray was known to refute the conclusions of the scientific community regarding climate change.

But rather than taking a scientific view, Hewson claimed that the bigger issue is around the risks to the assets in the Future Fund portfolio.

""There are many ways in which we could see a rapid shift to the low carbon economy in the coming years. Under any of those scenarios, we will see rapid direct or indirect re-pricing of carbon, and then the Future Fund will be unable to sell any stranded assets and so it must start planning now."

"Australia's retirees cannot afford another sub-prime crisis," he added.

John Connor, CEO of The Climate Institute, which operates AODP in Australia, added that as a carbon and resource intensive economy, Australia has a massive risk exposure to climate change and its regulation.

For our largest pool of capital to ignore this is a problem for government and regulators", but most of all for citizens and taxpayers who are entitled to know what the board of guardians are actually doing," he concluded.

The AODP issued disclosure requests to the world's largest 1,000 asset owners in August and will publish its first global index of funds later this year.