Shein: China fashion giant faces US calls for probe over Uyghur claims
The company also said that it currently has no plans for a listing on Wall Street
The letter to the Wall Street watchdog comes amid expectations the firm may sell its shares in the US.
The company also said that it currently has no plans for a listing on Wall Street.
The letter, which was signed by two dozen Republican and Democrat lawmakers, cited "credible allegations of utilising underpaid and forced labour".
It also called on the Securities and Exchange Commission (SEC) to force Shein to independently audit and verify "that the company does not use Uyghur forced labour", before it was allowed to sell shares in the US.
Human rights groups and Western governments, including the US and UK, have accused China of forced labour and internment of Uyghurs, a mainly Muslim ethnic minority.
In December 2020, research seen by the BBC showed that up to half a million people were being forced to pick cotton in Xinjiang. Beijing denies any rights abuses.
Some Western brands have removed Xinjiang cotton from their supply chains, and the US has passed new regulations on the import of goods from Xinjiang which require firms to prove they were not produced using forced labour.
Shein- which was founded in Nanjing, China in 2008 - is now headquartered in Singapore.
It has been winning over young shoppers in the US, UK and Europe by producing fast fashion even faster, and often at cheaper prices, than many of its rivals such as Boohoo or Asos.
It has collaborated with celebrities and influencers to build its online following, and in 2021, its mobile app briefly jumped ahead of Amazon on iOS and Android app charts as the most downloaded shopping app in the US.
Shein reportedly relies on thousands of third-party suppliers in China to produce batches of clothes, which it orders again if they perform well with customers.
In the past, the firm has faced allegations of poor working conditions where workers allegedly worked 75-hour weeks.
