Officials in Australia are investigating 20 vocational colleges and education providers in Melbourne that are suspected of violating immigration laws, The Age, a local newspaper, reported.

The investigations follow a raid on several Melbourne businesses where immigration authorities discovered fake education documents. International students who wish to apply for permanent residence need to provide diplomas and work histories.

Universities still attract most foreign students who come to Australia to study, but vocational training is the fastest-growing sector of international study there. The number of international students enrolled in vocational-education programs in Australia jumped 46 percent in 2008 over the previous year. Last year overseas enrollments exceeded a record 500,000 students, earning the country $10-billion (U.S.).

The country’s relatively liberal immigration policy gives priority to overseas vocational students seeking residency under the government’s Migration Occupations in Demand List. Hospitality, business, and professional cooking classes are among the most popular courses. —Martha Ann Overland