The cost of detaining asylum seekers in Australia's Nauru and Manus Island detention centres is set to blowout.
A senate committee has been told the federal government will have to find extra cash in the mid-year budget review to keep the camps going.
The secretray of the Immigration Department, Martin Bowles, say the current budget allocation of 845 million US dollars won't last until the end of 2013/14.
He told the hearing that they need hundreds of millions more.