A growing number of Chinese university students are being targeted by loan sharks who demand nude photographs as collateral, according to a report in the Guangzhou-based Southern Metropolis Daily.

"The nude photos will be made public if the borrowers fail to repay their debts with interest," an insider was quoted as saying by the newspaper.

Some students who failed to repay their debts in time have sought police help, accompanied by their parents, after being threatened with sexual violence or having their nude photos published online, the newspaper said.

One female university student, who was referred to as Li Li to protect her identity, said the loan sharks asked students to provide photocopies of their identity cards, student cards and family data, plus their nude photos, before they were granted a loan.

"Many students have borrowed the money from the loan shark groups by leaving their nude photos to the lenders," Li told local media.

"The interest rate usually reach more than 30 percent a year, and a student can borrow from several hundred yuan to many thousand yuan according to the materials and data they offer."

The loan amount is often contingent on the level of the borrower's education, she said.

Li borrowed money from a loan shark group to start a business in February and said she had since been threaten to repay her debts, else her nude photos will be published.

Zhang Xinnian, a lawyer from Beijing, said publishing other people's nude photographs was a serious infringement of their personal privacy.

He urged victims to actively seek police help or go to court to protect their legal interests.

Local police did not comment on the cases on Tuesday.