Australia's property boom won't end smoothly and there is a "dramatic" crash on the horizon according to a leading economic group.

The Organisation for Economic Cooperation and Development (OECD) warned the national property boom which has attracted investors from across the globe could be about to crash.

The end of the boom will reportedly be caused by ''uncertainties on future economic policy ahead of the Federal election," the report states.

"Domestically, the unwinding of housing-market tensions to date may presage dramatic and destabilising developments, rather than herald a soft landing."

The reports warns Australia's dependence on commodity markets in China as another factor that could see the property market plummet.

"(Chinese markets remain) an important source of uncertainty and risk," the report said.

With Sydney listed as one of the most expensive cities in the world, a dip in the buyer and investor property market could have serious effects on the county's national economy.