A young woman had to be rescued out of a freezing river in east China after she undressed and jumped in voluntarily.

The naked woman was spotted on the riverbank shortly before taking the plunge, and several witnesses ran to the water's edge.

One young man braved the cold water and jumped in to save her, however, once the deed was done, the man was left to fend for himself.

Unappreciated hero: A Chinese woman was saved by a Good Samaritan after jumping into a river, left, but her rescuer was abandoned in the freezing water, right

The naked woman appeared by the Nanjing river in east China's Jiangsu Province in nothing but her birthday suit on Sunday afternoon, and jumped in.

A local university student went after her and pulled her out of the water, after which she was helped by a large group of bystanders.

Photographs of the event posted on Chinese microblogging site Sina Weibo shows the brave saviour left to his own devices in the freezing water, as the crowd huddles around the naked woman.

'Everyone was watching the naked woman, but no one lent a hand to the rescuer. It was so freezing,' on Sina Weibo used said accoridng to Shanghaiist.com.

Nippy out there: The woman was seen naked on the riverbank in east China's Jiangsu Province on Sunday afternoon, before jumping into the cold water