The Gucci employees said in the letter that they had to work overtime without being paid properly and even had to ask permission from their superior before drinking water, and they couldn't take more than five minutes to use the toilet.
Another former empolyee said she had to stand for more than ten hours a day when she was working for Gucci even during her pregnancy. She also complained that the company did not allow her to eat fruits or snacks during breaks.
As a result of the overtime work and late nightshifts mandated at the outlets, more than one pregnant saleswoman had a miscarriage, claimed the letter, which was published online in late September.
The letter also claimed that workers at the shops had to stand for more than 12 hours a day and would still not receive overtime pay. The company's outlets usually close at 10 pm but, according to the letter, workers had to stay from 2 am to 3 am to conduct inventory checks.
One of the letter writers, who would only gave his surname, He, said that if wares were missing from a certain store, employees there had to pay for the loss.
Staff at Gucci's Shenzhen stores lost more than 70,000 yuan ($11,111) from their salaries when 16 items in their charge were found to have disappeared from 2009 to the end of August.
He said that happened even though Gucci had had its products insured.
"Gucci gets double compensation (from its staff and the insurance company) when its products are stolen or lost," He was quoted by Xinhua as saying.
In the letter, the five employees asked for the overtime pay they said is owed to them and for compensation for health damages.
Gucci responded to the claims by saying that the company has always paid close attention to its employees’ welfare, and it has been investigating into the complaints and will deal with them properly as soon as possible.
Gucci has issued a notice asking staff members not to speak to reporters about the matter, according to a report by Xinhua News Agency.
Insiders said the accusations will cast a shadow over Gucci's expansion into China's mainland.
"Chinese people should boycott Gucci products," said a netizen who used the name "an angry bird".
Yang Qianwu, a lawyer from the Shenzhen-based Dacheng Law Firm, encouraged the city's labor supervision departments to take steps to safeguard workers' legal rights and interests.
"Relevant labor departments have the right and obligation to help workers and protect their legal interests," Yang said.
Wang Hongli, deputy director of the Shenzhen Trade Unions's rights and interest protection department, said many international companies never allowed their employees to form unions in Shenzhen, making it difficult for union officials to collect evidence in labor disputes.
He encouraged Gucci employees to report maltreatment to the Shenzhen Trade Union.
An official from the Shenzhen Luohu district bureau of labor and human resources has promised to probe into the case.