The European Commission announced the request a day after confirming it was investigating the low-cost e-commerce platform for not abiding by the bloc's consumer protection rules.

"The Commission is requesting Shein to provide internal documents and more detailed information on risks linked to the presence of illegal content and goods on its marketplace," it said.

The EU's regulator also asked for information on other issues, including the "transparency of its recommender systems" and protection of users' personal data.

"Shein must provide the necessary information by 27 February," the commission said.

"Based on the assessment of the replies, the Commission will determine the next steps".

The request could lead to a probe under the EU's Digital Services Act (DSA), a mammoth law that forces the world's largest tech firms to do more to protect European consumers online.

"Shein shares the Commission's objective of ensuring that EU consumers can shop online with peace of mind, we have received the request for information and are working to respond promptly," the company said.

Brussels has already launched a separate investigation into the popular fast-fashion site, which was founded in China in 2012 and is now headquartered in Singapore, for not doing enough to prevent the sale of products that do not meet European standards.

After the probe was announced, the company said it would "engage" its partners at EU and national government-level.

Shein is not the only online retailer originally from China in the crosshairs of Brussels over similar issues.

The commission in October opened an investigation against Temu, which sells a vast array of goods at low costs.

A commission spokesman explained many products tested were not compliant with EU rules and safety standards.

This could have serious consequences, the spokesman added, citing as examples a baby's pacifier that could come apart and choke the child, or a light fitting that could cause an electric shock.