The authors of a new study into Australia's skilled migration program say the system is being hijacked.

The study shows that between 2004 and 2006 there was a 167 per cent increase in overseas students starting vocational courses in hairdressing and cooking.

After graduating, students can gain permanent residence visas because they are considered skilled migrants who are needed in Australia.

During the two-year course, students are required to complete 900 hours of work experience to qualify for the work visa.

Study co-author, Bob Kinnaird, says the system is poorly regulated and some students are doing unpaid work to meet the criteria.

"In some cases, students are actually paying the employer to get the chance to clock up 900 hours because they're so desperate to get the work visa," he said.

"That situation is really unacceptable."

http://www.abc.net.au/news/newsitems/200703/s1883403.htm