Kappa Girl Huang Video - A 12 minute long sex video (sex tape) of a female employee - identified only by her surname - Huang, working at the Kappa store

It has emerged on Chinese internet via Bittorrent and the Chinese peer-to-peer application Xunlei, reports Shanghaiist.com.

Shanghai police have detained the woman for allegedly filming herself having sex and then posting the video on the Internet.

"Huang was detained by police on suspicion of disseminating pornographic materials," the Shanghai Public Security Bureau (PSB) said in a statement (in Chinese)

Pornography is illegal in China, but remains widely accessible on the Internet. The PSB statement, released Friday, did not say when Huang was detained.

A sexually explicit conversation between her and her boyfriend has been translated from Shanghainese to Mandarin and is available all over the internet now.

Intrigued, people started showing up at the Kappa store with cameras in hand trying to catch a glimpse of her.

Under Chinese law, anyone who films or uploads sex videos onto the internet is guilty of distributing pornographic content.

Photo of 'Kappa Girl' is from Shanghaiist.com. Videos of 'Kappa Girl' available here.