About 70 University of Auckland medical students posted overseas are being called back home – an unprecedented step amid the global spread of Covid-19.

The university says another 150 students could also be affected if its suspension stays in place for the rest of the academic year.

The students have been based at hospitals and clinics around the world as part of medical electives, which allow them to gain hands-on experience in their specific fields.

"To be fair to all fifth and sixth year students, we decided to suspend all international placements, even to low-risk countries, until further notice," Faculty of Medical and Health Sciences dean Professor John Fraser said.

He said students would not be academically disadvantaged by the change, and placements in New Zealand would be arranged for those having to return home.

Students have also been advised that any policies placed after January 30 with the university's travel insurance provider, Allianz, would be deemed to have been booked "with awareness of the coronavirus".

That meant any medical costs, cancellation or disruption to travel plans associated with the outbreak would not be covered by the company.

Fraser said this week's decision was made to avoid the potential for students being trapped in countries, should international travel conditions change.

"Most are in low-risk countries, but there are some in regions such as Africa where things could change very rapidly," he said.

The decision was made by a senior group of faculty members – including infectious disease experts - responsible for delivering the international programme.

"We have been reviewing the programme for the past three months and monitoring global developments," Fraser said.

"The most important factor in Monday's decision was the spread of the virus into countries where monitoring and containment would be more difficult and where we currently have students."

He said the first priority was student welfare.

"This is not a situation that has ever happened before, certainly in my memory."

The Covid-19 crisis has already caused massive disruption to New Zealand universities.

Last month, Victoria University's vice chancellor Grant Guilford said universities could lose up to $300m a year as long as New Zealand's current travel bans stayed in place.

More than 6500 Chinese students who were enrolled to study in New Zealand this year are still stuck at home.