The chair of a committee of MPs has written to the London Stock Exchange with concerns over the fashion retailer.

A Shein representative declined to provide a direct answer when asked by a British parliamentary committee on Tuesday whether the online fast-fashion retailer uses cotton from China, a key issue for potential investors concerned about its supply chain.

A lawyer for Shein summoned to a British parliamentary hearing has evaded questions on whether the fast-fashion giant sells products containing cotton from China.

Yinan Zhu declined to say whether it retailer's suppliers used Chinese cotton amid concerns over forced labour.

A Shein representative declined to provide a direct answer when asked by a British parliamentary committee on Tuesday whether the online fast-fashion retailer uses cotton from China in its products. It was the first opportunity for British lawmakers to publicly question the company which is working towards an initial public offering in London.

A representative of fast fashion clothing brand Shein repeatedly refuses to deny that the company uses cotton sourced from China, where practices are widely speculated to use modern slavery.