Australian medical students face a A$200,000 (£79,000) bill for their training at the University of Melbourne.
Critics say the fees, potentially payable from 2005, breach the commitment given by Prime Minister John Howard when he denied that any Australian student would be forced to pay A$100,000 for a degree.
Australia's 12 universities with medical schools already earn more than A$50 million a year from international student fees. They expect to generate even more income in 2005 when, for the first time, they will be able to admit Australians prepared to pay the full A$200,000-plus cost of the five to six-year courses.
Nationally, some 1,500 foreign students - the majority from Asia - are enrolled, paying up to A$40,000 a year. A further 800 Australian students may take up the full-fee option in 2005, although they will pay less.
Melbourne this year enrolled more than 500 foreign medical students. With an annual fee of A$40,000, they are contributing at least A$20 million to the university.
Australian full-fee payers are likely to have to find A$35,000 a year to undertake the six-year Melbourne course.
The National Tertiary Education Union drew attention to Mr Howard's denial.
Union president Carolyn Allport said few Australian families could afford to pay A$100,000 to send their children to university.
Dr Allport said that under the Government's policies, universities would be allowed to increase the number of full-fee paying domestic students. "This means that more people will be able to buy places at university even when students with higher marks are missing out on government-supported places," she said.
She added: "Entry into university should be about your ability not your bank balance."
Dr Allport said that as 25 of the 38 public universities had decided to increase their Higher Education Contribution Scheme charges next year by up to 25 per cent, most Australian students would have to pay more. Three universities have yet to decide and ten opted to make no change.
The Government is facing a crisis in the supply of medical doctors and has decided to create five more medical schools. It has made it easier for international medical students to remain in Australia after they graduate.