The University of Sydney had a total of 61,300 students last year and Melbourne University had 52,750 students,compared to about 24,000 students at Oxford University and about 20,000 at Harvard.

Harvard's then-president Drew Gilpin Faust made about $2.5 million in today's Australian dollar terms in 2017.

John Egan,principal at remuneration and governance advisory firm Egan Associates,said the vice-chancellors of Australia's biggest universities are effectively running small cities.

"They have more than 50,000 people in their precinct every week,they have to provide services,parking and at the same time,attract funds and maintain a research presence,"he said.

Catriona Jackson,chief executive of Universities Australia,said:"Australian university vice-chancellors run very large,complex organisations. Their remuneration is thoroughly benchmarked."

However,Australian universities'growing student populations are being taught by a more casualised teaching staff inclassrooms that are some of the most crowded,according to the latest QS World University Rankings.

Alison Barnes,president of the National Tertiary Education Union,said:"Vice-chancellors'remuneration is just shocking in the context of a sector where casualisation is at alarming,epidemic levels and universities are under so much pressure.

"The top vice-chancellors are making three times as much as the prime minister."

At the University of Queensland,where departing vice-chancellor Peter Høj's 2018 pay packet of $1.2 million matches Oxford's head Louise Richardson's salary,the search is on for a top replacement.

A spokeswoman said Professor Høj will leave the role in June next year,giving the university"time for an extensive recruitment process to find the next vice-chancellor".

"[A] selection committee will be assisted by a search firm with international reach and the position will also be advertised internationally,"the spokeswoman said.

The search could well expand to commercial executives,in line with a move away from seasoned academics to take on the top job at some Australian universities.

RMIT's vice-chancellor,Martin Bean,who earns $1.1 million,does not have an academic background. He does hold a bachelor of education degree and has held leadership roles at Microsoft,Novell and other technology companies.

A number of other vice-chancellors have also forged career paths largely outside academia,including the University of Technology Sydney's Attila Brungs,who previously worked at management consulting firm McKinsey and Company and CSIRO.

Mr Egan said this is a growing trend.

"Not all universities today have a vice-chancellor who would be recognised as the most distinguished academic in the university,whereas if you go back a generation that would generally have been of the defining attributes of the vice-chancellor,"he said.

"Today the vice-chancellor is running a business."