“An investigation by Beijing Youth Daily shows that in some money lending groups, female university students’ ‘naked holding’ has already become an open secret,” it wrote, referring to the practice of women photographing themselves naked holding their ID card as a guarantee of repayment.

A man with the online handle of Beijing Ninth Uncle on Weibo, China’s Twitter-like social media platform, said he was gathering evidence that women from many different walks of life, including farmers and university students, were falling afoul of the lenders’ demands. The man said he was a writer on the finance industry.

“With ‘naked holding’ they can get two to five times the amount of money, but when they can’t repay some have been threatened with publishing the photographs, and some lenders are even demanding the female students provide sexual services,” Beijing Youth Daily wrote.

It described the case of a university student from Jiangsu Province in central China, whom it gave the pseudonym of Lin Xiao. Her troubles began, it said, when she borrowed 500 renminbi, about $75, from a lender in February to open an online store. At 30 percent interest on the one-week loan, she quickly needed more money to repay the debt, eventually borrowing about 120,000 renminbi from 15 people, a sum that soon ballooned into 250,000 renminbi (about $38,000) at the high interest rate.

Eventually, the woman supplied a nude photograph of herself in exchange for a larger loan to try to escape her debt, including personal information such as contact numbers and addresses for family members. When she could not repay, the lender threatened to show the photographs to her family and friends, the newspaper reported.