Riot police officers stood guard in the centre of the French capital as Shein prepared to open its first physical store on the sixth floor of the BHV department store, an iconic building that has stood across from Paris City Hall since 1856.

People queued outside the luxury department store ahead of the scheduled controversial opening at 1200 GMT Wednesday, while children's rights activists staged a protest nearby.

"Protect children, not Shein," one of the signs read.

Protesters distributed red flyers, denouncing "suspected forced labour", "pollution" and "overproduction", and urging passersby to sign a petition against Shein's presence inside the Paris department store.

Shein, which was founded in China, has faced criticism over working conditions at its factories and the environmental impact of its ultra-fast fashion business model, and its arrival in France has been opposed by politicians, unions, and top fashion brands.

Just days before the planned opening, a new controversy erupted over the sale of childlike sex dolls on Shein's platform.

The discovery triggered a new political outcry and the opening of a judicial investigation.

The Paris prosecutor's office said ahead of the store's launch that it had opened investigations against Shein, and also rival online retailers AliExpress, Temu and Wish, over the sale of the sex dolls.

The probes were for distributing "messages that are violent, pornographic or improper, and accessible to minors", the office has said.

French media published a photo of one of the dolls sold on the platform, accompanied by an explicitly sexual caption.

The pictured doll measured around 80 centimetres (30 inches) in height and held a teddy bear.

- 'Malfunction' -

Shein, which was founded in China in 2012 but is now based in Singapore, has pledged to "fully cooperate" with French judicial authorities and announced it was imposing a ban on all sex dolls.

Shein's spokesman in France, Quentin Ruffat, has chalked up the sale of the dolls to "a malfunction in our processes and governance".

Frederic Merlin, the 34-year-old director of the SGM company that operates BHV, admitted on Tuesday that he considered pulling the plug on the partnership with Shein after the latest uproar but then changed his mind.

He said he was confident about the Shein products that will be sold at his department store, and denounced a "general hypocrisy" surrounding Shein.

"Shein has 25 million customers in France," Merlin told BFMTV/RMC on Wednesday.

Shein's meteoric rise has been a bane for traditional retail fashion companies.

Critics fear that Shein will further hurt stores in France, some of which have had to lay off staff or close.

Shein is also scheduled to open five shops in other French cities, including Dijon, Grenoble and Reims.

ole-hrc-as-sw/ah/yad