Australia's apex student body has asked the government to stop treating overseas students as "cash cows" and provide greater protection to them from educational scams and sub-standard colleges.

David Barrow, President of National Union of Students (NUS) said there was not enough protection to prevent collapses like the recent Sydney-based Sterling College that has left the fate of many students in limbo.

The college went into voluntary administration on Monday, leaving about 500 students - many of them from overseas - facing uncertainty and financial loss.

Education authorities in the country are probing several colleges for posing "high risk" for the overseas students and being sub-standard, the media reported.

It was the second in line after a college in Melbourne that was shut down earlier this month. The government has said it will deal with the problem of aggrieved foreign students.

"This happens every five or six months," Barrow said adding: "It's time the government stopped treating these students like cash cows and made them their responsibility."

"The students from Sterling College are being screwed over. Are you going to be screwed over?" he asked a crowd of around 200 students on Thursday.

"We're telling the government enough is enough," he was quoted as saying by the AAP.