International students contribute an estimated £312 million to the Scottish economy each year, new figures suggest.

Even taking into account the impact on public services such as the NHS, the net benefit is about £257 million each year, according to research by PwC.

Last year, 34,670 students from outside the European Union (EU) travelled to Scotland to study at one of the country's 18 higher education institutions, it said.

But PwC warned that the British immigration system is viewed as particularly complex, impacting on international students' overall experience of studying in the UK and making it difficult to secure work once they have graduated.

Lindsey Paterson, a higher education specialist at PwC in Scotland, said: "Our Scottish universities and colleges are competing in a global marketplace and it's vital that government supports them in attracting the brightest academic talent not just from here in the UK, but from the EU and further afield.

"International students not only help to broaden our own students' vision and perspective in the classroom but have a major economic impact through their fees and consumer spending.

"With a lot at stake, not just for the Scottish and UK economy but for the future growth and prosperity of our higher education establishments, it's clear that more needs to be done to inform and improve immigration policies and targets."

PwC called on the UK Government to develop better data collection on migration so that "the real facts on inward and outward flows" can be charted.

It said the UK should follow the lead of Canada and Australia and classify students as temporary visitors, not migrants, and make it easier for international students to work in the UK for a few years after graduation.

This would be good for universities, business and for Britain's long-term relations with the global business community in cases where graduates return to their home countries, PwC said.