Figures obtained by The Australian show 7061 student visas were cancelled in the last financial year, with 4930 cancelled the previous year and 1978 cancellations in the 2012 financial year.

Responding to a spike in “non-genuine” students, most commonly recruited by third-party broking services based offshore, the federal government has quietly stepped up a campaign to assist tertiary colleges in identifying real students.

The Department of Immigration and Border Protection said it had also identified about 1000 “course hopping” international students, who arrived on streamlined student visas but later transferred to unaccredited colleges.

The recent introduction of a streamlined visa process for international students enrolling at accredited providers has been a boon for the industry, by providing an easier route for prospective students into the country.

But, once here, some students would move to cheaper colleges that did not qualify for the streamlined visa program, a practice that is illegal.

The department said students caught “course hopping” had been asked for explanations, with 457 visas cancelled to date and others still being processed.

Thomson Ch’ng, president of the Council of International Students Australia, said not only were some students changing courses, but also others were failing to turn up altogether.

On some occasions, Mr Ch’ng said, agents would organise visas even though they knew students weren’t genuine because this was an easier avenue for entry.

“Ghost students are common in some colleges, the issue being where they are if they are not ­attending classes, but are here on student visas,” he said.

“This is definitely a loophole. I’m not saying all agents are operating unscrupulously, but there are a few rotten apples out there that are leading the way in sending non-genuine students to Australia, and it’s becoming more widespread.”

International students have contributed $15.74 billion to the economy in the last financial year according to the Department of Education, the highest figure since a peak of $16.4bn in 2010.

In November, Australia’s largest listed education company, Navitas, said it would be slowing overseas enrolments after growing concerns some were enrolling merely for visa reasons. It had identified irregularities in enrolments from Nepalese and Indian recruiters, with a number of cases of fraudulent documentation and higher incidences of student withdrawals.

Yesterday, Navitas chief executive Rod Jones said the company had immediately applied risk-mitigation strategies, including the cancellation of some 40 agent partnerships, and was initiating in-country face to face interviews with students where required.

The Education Department has begun warning universities and colleges about the possible risk of irregularities in financial documentation from Nepal.

The University of Wollongong in NSW said procedures had been tightened and there were now restrictions on the types of financial documents that were acceptable. International students must show sufficient funds to cover tuition and living expenses, as well as the cost of the trip home. There are also English language requirements.

The Australian has identified a number of brokers in Nepal who have been blacklisted by local colleges, including the Kangaroo Education Foundation and Global Village International Education in Kathmandu, which advertises a 100 per cent visa success rate.

Tougher screening has seen the number of student visas granted from India fall from 91 per cent of all applications in the third quarter of 2013 to 82 per cent for the corresponding last year while visas granted to Nepalese students fell five percentage points to 91 per cent.