Thousands of teenagers from Asian countries are increasingly being sent to NSW to finish their studies at the state's public high schools, with the latest figures revealing a 25 per cent increase in new, full fee-paying international students in just 12 months.

The students pay up to $14,000 a year in fees to study in the public system, often on top of about $300 a week to live with an Australian family, raising at least $33 million each year, although the figure could be much higher.

Chinese students now account for more than 60 per cent of international students following a change in visa regulations last year. Credit:Michele Mossop

Demand to secure a spot in NSW public schools is now so strong that statistics from the NSW Department of Education show the number of Australian families needed to house the extra international students has soared 400 per cent in just four years.

In 2010, only 276 families were required to host international students, but in 2014, 1129 families were needed and a tender process to find more families to cater for the expected influx later this year has just closed.