They enter Australia on student visas to take up a recognised course, but switch to a cheaper unrecognised one soon after their arrival, in a breach of visa conditions.
A spike in "course-hopping" by foreign students has led the Australian government to cancel their visas.
Last year, the government cancelled more than 7,000 student visas as it sought to curb fraudulent practices in the A$15.7 billion (S$16.5 billion) international education industry.
"Course-hopping" was the most common breach and accounted for 4,458 cancellations.
Others include falsifying English test results and failure to provide proper papers to show that the student can afford to live and study in the country.
Figures provided to The Sunday Times by the Department of Immigration and Border Protection showed that 1,120 Chinese had their student visas cancelled, followed by Vietnamese (896), South Koreans (787), Indians (548), Thais (400), Indonesians (321) and Malaysians (308).
Australia had 583,714 international students in total last year, including 153,155 from China, 62,346 from India and 29,584 from Vietnam.
There were 8,438 from Singapore.
To obtain a student visa for Australia, applicants need to be registered for a recognised course, show they can afford to study and live in Australia, and have adequate English skills.
The visas typically allow students to work for up to 40 hours a fortnight during term time, and unlimited hours during holidays, while family members can accompany and work for up to 40 hours a fortnight.
Navitas, the largest listed education provider in Australia, said it had slowed enrolment over concerns about "course-hopping" and other fraudulent behaviour.
It said such cases had gone up after the government made it easier for students to obtain visas and put the onus on universities and colleges to check documents and assess students.
"What we started seeing last year was a large increase in applications from Nepal and India," Mr James Fuller, Navitas' public and investor relations manager, told The Sunday Times.
"When we looked closer, we realised not all were genuine students."
He said Navitas detected a "couple of hundred fraudulent visas" from among its roughly 10,000 students last year.
There were 300 to 400 students from Singapore but none was found to have any problems.
Government figures showed that 7,061 visas were cancelled last year, up from 4,930 in 2013, and 1,978 in 2012.
The crackdown followed an online campaign by the government last year to warn foreign students and education providers of the consequences of "course-hopping".
"There is definitely a loophole," Mr Thomson Ch'ng, president of the Council of International Students Australia, told The Australian.
He said: "(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."
This article was first published on Feb 1, 2015.
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