Exiled Chinese dissidents and members of persecuted ethnic groups have also reported harassment from Chinese authorities, including threatening phonecalls.
Chinese officials said no authority would contact students on their mobile to demand money.
The warning comes as the university sector attempts to lure back lucrative international students online and prepare for any possible relaxation of virus travel restrictions.
Education is Australia’s fourth-largest trade — behind iron ore, coal and natural gas — with more than 500,000 international students enrolled last year, bringing about Aus$37 billion into the economy.
The closure of its borders to travelers due to the coronavirus pandemic has crippled the sector and heightened tensions with Beijing has further threatened the flow of students to the country.
Last month China’s ministry of education warned students about “multiple discriminatory incidents against Asians in Australia” during the pandemic and discouraged students from returning to the country when the borders reopened.