The government in Henan province is investigating a plainclothes police officer after a grocery store owner was blackmailed.

Fan Yuege, from Zhengzhou Public Security Bureau, was exposed in an online video demanding cash.

In the video, uploaded on Sunday, Fan agreed not to cause the victim any more trouble after receiving the cash.

The Internet user who uploaded the video said that in early January Fan and four other officers broke into the grocery store and detained two employees, claiming they had found counterfeit banknotes in the store, according to a report in China Youth Daily.

Liu Zhichuang, owner of the store, said Fan released a sales assistant after receiving 1,000 yuan. He released the other employee after being given another 4,000 yuan, but the incident was recorded by Liu using a hidden camera.

A police officer with Zhengzhou Public Security Bureau, speaking anonymously, told the newspaper the man in the video is Fan. He also said Fan had been punished in 2011 for pretending to be a traffic policeman and charging fees illegally.

The bureau vowed to investigate the case.