Many universities are too relaxed about these relationships and the "murky space" needs to be reviewed, according to Australian Council of Graduate Research convenor Denise Cuthbert.

The RMIT professor said a massive power imbalance meant that students were unable to freely consent to sexual activity with lecturers, tutors and supervisors.

"High ethical standards are quite properly applied to our research activities and yet there is an absence of these with our dealings with students."

Professor Cuthbert and her colleague Fiona Zammit are leading the charge for new professional and ethical standards for academics.

These would operate in a similar manner to those that exist for doctors, psychologists, nurses and lawyers.

The Medical Board of Australia prohibits doctors from having a sexual relationship with a patient, even when consent is provided.

While universities discourage relationships between staff and students, most acknowledge that they sometimes occur and have policies to manage the conflicts of interest that may arise.

This includes ensuring staff don't mark the work of students they are in a relationship with, make decisions about scholarships they are vying for or remain their main supervisor.

"It is almost like the credibility of the assessment process is the primary guidance rather than the welfare of the students," Ms Zammit said.

"These students have a lot to lose if something goes wrong and they can't get through their degree."

A landmark Australian Human Rights Commission survey into sexual assault and harassment at universities found that postgraduate students were particularly vulnerable to sexual harassment from university staff.

The survey, released in August, found that 10 per cent of postgraduate students who reported being sexually harassed said it involved their tutor or lecturer. This compared to 6 per cent of undergraduate students.

The Council of Australian Postgraduate Associations and the National Union of Students support the push for a ban on sexual relationships between staff and students.

"Something needs to change," the Associations' national president Peter Derbyshire said.

He's been contacted by postgraduate students who have ended relationships with their supervisors and then found that they've become difficult to work with.

"Postgraduate students don't like complaining when it is risking their careers and futures," he said. "There's a real power imbalance."

National Union of Students president Sophie Johnson said academics had a duty of care for students and staff-student relationships put this at risk.

"They are there to provide for a student's education and it shouldn't go further than that," she said.

In its response to the Commission's survey, Universities Australia said it would develop guidelines for the interaction between supervisors and postgraduate students in consultation with students and academics.

"There is also a growing conversation across every sector of society about the importance of consent and respectful relationships. Universities are part of that crucial conversation and will continue to work with their students, staff, and policy experts to inform their policies and initiatives," Universities Australia's Chief Executive Belinda Robinson said.

Physicist Katie Mack, a former postdoctoral fellow at the University of Melbourne who will soon be working at North Carolina State University, said meaningful consent was impossible when a staff member had any direct influence over a student's advancement.

"Even when the influence is not clear, there is an inherent power imbalance due to academic status," she said.

"It's possible that some small fraction of these imbalanced relationships work out fine in the end by some measure, but the risks and the potential for harm to the student and others are not worth it."

National Tertiary Education Union president Jeannie Rea said banning relationships between staff and students could lead to more secrecy and potential damage to students.

"Staff should know that they should not pursue a relationship while their professional duties or even proximity intersect with a student," she said.