Botswanan students at the university have reported scores of students on government scholarships have been called home since the end of last year.

The students were called back if they had failed a subject or asked for an extension, even though some had been at the university more than three years and were about to graduate.

Botswana was the third largest contributor of international students to the university in 2004 with 99 enrolments, but numbers are now down to 28.

The Botswana economy is heavily reliant on the diamond trade, which has taken a hit during the downturn.

The university signed a post-graduate scholarships agreement with the country last year and is planning a graduation ceremony there later this year.

Newcastle University Student Association international convenor Eduardo Carvajal said the full effects of the downturn were unlikely to be visible until year's end.

He said students from vulnerable Asian countries were also starting to waver.

"Particularly if they are from Malaysia, students are living on noodles just to get by," he said.

In contrast, the university has had a surge of students from Saudi Arabia since the downturn, partly because of the competitive Australian dollar. International students are worth more than $36 million a year in direct fees to the university.

For every four overseas students who come to Australia to study, more than one job is created.

University global relations deputy vice-chancellor Kevin McConkey said international student numbers were up 23 per cent in 2009 despite the downturn.

"In 2008, international student enrolments totalled 940 equivalent full-time student load at the end of March. In 2009, the figure is 1160," he said.

The Bostwana High Commission did not return The Herald's inquiries.