Shein factory employees are working 18-hour days for pennies per garment and washing their hair on lunch breaks because they have so little time off, new report finds

The human cost of maintaining a fast-fashion company's business model has been shown by an undercover investigation.

According to an undercover investigation by Channel 4 and The i newspaper in the UK, workers in China that supply clothes to Shein often work up to 18 hours a day with no weekends and just one day off a month.

A woman using a fake name got a job in two factories and secretly filmed what she saw. "Untold: Inside the Shein Machine" will be available to stream on All4 from Monday.

One worker in the footage said there was no such thing as Sundays here.

The first month's pay is not paid to workers at one of the factories because they don't make enough clothing for 500 pieces a day. A commission of just two cents per item is earned by many of these workers.

The investigation found that at the second factory shown in the footage, workers are paid just under 4 cents for every garment they make.

If an employee makes a mistake, they will be fined two-thirds of their daily wages. Female employees in one of the factories wash their hair on their lunch breaks because there is not enough time after work.

The material shown in the investigation would violate the Code of Conduct agreed to by every Shein supplier, shein told Insider.

The company said its supplier code of conduct is based on International Labor Organization conventions and local laws and regulations.

The company said that partnerships that do not meet their standards will be terminated. Specific information from Channel 4 has been requested by us.

Shein has grown to become the largest fast fashion company in the world with a valuation of $100 billion in April. Customers often say their items break down very quickly, and designers often claim Shein copies their styles and sells them for cheaper, stealing business from them.