All employees of a chain supermarket in Hangzhou, east China's Zhejiang Province, have to draw chess pieces at the exit for staff before they leave, only to prove they are innocent or have to be body-searched.

Show me your pocket! It's our rule.

This practice, draw of the luck or innocence, has been in place ever since the Auchan supermarket opened in the city, according to a report by Kingboo newspaper on Tuesday.

Ms Zhang, an employee of Auchan supermarket, said the strange security check system has been used by her employer for a couple of years. All staff must pick a chess piece without looking at the color, to determine if they will be searched or not.

"You can leave straight away if you pick up a white chess piece at the staff's exit, but if you get a black one, your pockets will be thoroughly searched whether you are male or female, regular staff or a manager, " Zhang said. "It insults my dignity," she added angrily.

At the beginning, she objected to the regulation, but had to put up with it because few staff dared to complain about the checks.

The assistant manager of Auchan Hangzhou branch claimed that the regulation has been carried out by staff voluntarily since the shop opened.

"The company has never forced it on employees," he explained, "it just reminds them not to take things that don't belong to them."

A lawyer from Xingyun Law Office, Wei Yongqiang, said the regulation is illegal, and may infringe employees' human rights, from a legal point of view.

The regulation in fact discriminates against people who work for the supermarket, Wei said.

Wei pointed out that in other countries, supermarkets that have such "ridiculous" regulations may be subject to lawsuits.

"The regulation should be suspended as soon as possible," Wei added.

An unnamed official at the Hangzhou Municipal Labor and Social Security Bureau said they have begun to look into the issue, and would take measures if any problems were found.

The official also suggested that it would be better for supermarket staff to complain directly to the Hangzhou Labor Union, or even sue the company with union support.