Australia Sunday gave 7,500 boatpeople until October to file a claim proving they are genuine refugees or be kicked out, declaring the "game is up" for illegal arrivals ripping off taxpayers.

Before the conservatives took power and adopted a tough line on the issue in 2013, an estimated 50,000 asylum-seekers flooded into Australia on more than 800 boats over the previous five years.

Hundreds more, many from war-torn Afghanistan, Sri Lanka and the Middle East, died at sea during the treacherous journey.

Of those arrivals, the old Labour government processed nearly 20,000, leaving 30,500 to the current administration.

Some 7,500 of them have yet to present their cases for asylum or are refusing to answer questions about their identity, while claiming welfare benefits, casting doubt on whether they really need protection.

Immigration Minister Peter Dutton said that if they fail to lodge a claim by October 1, they will be removed from the country and banned from re-entering.

"This is a very serious situation and it's costing Australian taxpayers hundreds of millions of dollars a year," he said.

"So if people think that they can rip the Australian taxpayer off, if people think they can con the Australian taxpayer, then I'm sorry, the game's up.

"We are prepared to support people who are legitimate refugees, but we aren't going to support people who are just accessing welfare ... and then refusing to provide any information in relation to their protection claim."

Refugee advocates reacted furiously, saying the government had sunk to "an impossible new low".

"For years, these men, women and children have been waiting patiently to go through the proper process to be assessed as refugees, and find permanent safety in Australia," said Shen Narayanasamy, human rights director of campaigners GetUp.

"Asylum claims are extremely complex, and involve hours of poring over legal documents and paperwork.

"Legal services are pushed to the limit forcing hundreds to forgo legal advice and interpreters, making their claims impossibly difficult to complete."

Dutton said the cost of processing and supporting the 50,000 boatpeople amounted to $1.4 billion a year.

Of the 30,500 left to the current government to deal with, 23,000 have applied for protection. So far, 3,000 have been assessed as not genuine refugees.

Source: Khaleej Times