Media investigations suggest the Federal Government could write off billions of dollars of higher education loans.

Documents obtained from the Parliamentary Budget Office under Freedom of Information show that as the number of bad debts soar, the government is looking at losing billions of dollars.

Reports say the Government is forecast to lose over $13.5 billion on just four years' worth of loans.

The total cost to the Federal Government of higher education will hit $20 billion in just over two years’ time — double the 2008 cost.

At the moment, students pay about 40 per cent of their university course fee, with the Government paying the rest.

The ministerial brief for Education Minister Simon Birmingham obtained by the ABC also reveals commonwealth-supported university places will jump by 50 per cent over the 10 years to 2018 to 712,200.

It said that the uncapping of university places alone has cost the Commonwealth almost $4 billion since being introduced.

The Government has not commented publicly on the revelation, but appears committed to university funding cuts and fee deregulation.

It is also considering changes to the scandal-plagued vocational education sector, which only adds to the fiscal problems.

The HELP loan system allows students to defer vital education payments until they can afford to pay them, and subsidises the interest rate on the ever-growing pile of debt.

Current forecasts say the amount never to be repaid on loans issued in 2018-19 alone will exceed $4.4 billion.

The figure is about four times higher than the loss from loans issued last financial year.

The Government’s latest budget update warned that over 20 per cent of debt issued in 2018-19 would not be repaid, at which time the average amount of debt is on track to hit $22,500.

Student numbers in higher education are tipped to rise, especially after the removal of caps on university places in 2009 to create the current “demand-driven” system.

The demand-driven system is forecast to cost about $10 billion over a decade, compared to the previous system.