Police in China have detained dozens of young women authors in a genre of gay erotica widely known in Asia as "boys' love" during a nationwide crackdown on online pornography, lawyers and activists familiar with the cases say.

The detentions since March have triggered debate on social media about the limits of free speech and the apparent sexist nature of the crackdown, while stirring sympathy for the authors, many of whom hail from low-income backgrounds.

"I just wanted to earn some money to ease my family's financial burden," one author of such works wrote in a May 25 post on microblogging platform Weibo before it was deleted.