Australia will be the worst-hit advanced economy from slowing Chinese investment growth, secretive International Monetary Fund research considered too politically sensitive for full publication shows.
Only Iran, Kazakhstan, Saudi Arabia, Zambia and Chile would suffer a bigger effect on their economies.
Interpretation of the IMF's modelling based on Treasury budget numbers also suggests it expects Australia's annual growth rate will be 2.5 per cent from 2020 onwards, making it harder to return the budget to surplus early next decade. 
The findings are a reality check for Australia's new Prime Minister Malcolm Turnbull and Treasurer Scott Morrison, who inherit a 10-year budget outlook that assumes the economy will grow at 3.5 per cent for five years after 2017-18.
Some economists, including at the Reserve Bank of Australia, have argued Australia's potential growth now might be less than 3 per cent, implying growth of less than 2 per cent if the IMF's predictions come true.
The research forms the basis of a series of coded warnings delivered by IMF managing director Christine Lagarde in recent weeks that have put emerging economies on notice to watch for potential shocks coming out of China.
While Ms Lagarde hasn't provided details of the findings in her speeches, deputy managing director Min Zhu told an audience in Dalian, China, in   September that a near halving of investment growth in the world's second-biggest economy over the next five years would cut about 1 percentage point from Australia's potential GDP growth rate by the end of that period.
The estimate - revealed in a photograph of slides presented at a World Economic Forum by Dr Zhu and seen by The Australian Financial Review - indicates Australia's economy will miss out on $16 billion a year of additional GDP by 2020.
Critically, the estimates are built on the Chinese government's expectation that investment in the country will fall steadily, from 46 per cent of GDP to about 35 per cent over the next five to 10 years.
The country's authorities, who are trying to engineer a shift away from a reliance on exports to more domestic sources of economic growth, expect investment growth to fall to 4.6 per cent over the next half decade, from an average of 9.5 per cent over the past five years.
For each percentage point decline in Chinese investment growth, Australia's potential gross domestic product falls by 0.2 of a percentage point, Dr Zhu's modelling predicts.
By contrast, the fallout for Brazil, Australia's main iron ore competitor, would be about half that amount per year, as would be the case for Germany. Countries likely to suffer the most from China's investment slowdown, the IMF said, would be Zambia and Chile, where growth would fall by twice as much as Australia.
If Chinese investment growth slows even faster, as many China experts believe, the affect on Australia and key commodity-based emerging economies will be correspondingly larger.
"This is the good scenario," said Alphabeta economist Andrew Charlton, who attended the briefing.
"This is the IMF pumping up everyone's tyres and not offending the Chinese scenario, where everything happens smoothly.
"Even if the Chinese government manages a smooth transition, the planned investment slowdown represents a 1 per cent drag on Australian GDP growth for the next decade."
Dr Charlton, a former adviser to former Labor prime minister Kevin Rudd and former senior Australian government official to Group of 20 economic summits, says the IMF research underscores the need for Australia to re-position itself to capture "the China of the future, not the past".
"There's not much we can do tearing our hair out about falling commodity prices. That's here to stay. This is about how quickly we adapt and seize new opportunities," he said.
Alphabeta, a consultancy firm, has identified and analysed what it describes as the "lucky eight" sectors outside mining that businesses and investors should focus on, not least because of the recent trade deal signed by former prime minister Tony Abbott with his Chinese counterpart.
These are retail, agriculture, tourism, financial services, clean energy and environmental services, healthcare, advanced manufacturing and education.
Key pointsModelling shows Australia's annual growth rate at 2.5 per cent from 2020.
Australia has been urged to adapt and seize new opportunities.