French prosecutors have opened an investigation into four multinational fashion retailers on suspicion of concealing and profiting from crimes against humanity in China’s Xinjiang region by sourcing goods produced using forced Uyghur labour.

Judicial sources confirmed to French media on Friday the investigation concerned Uniqlo France, owned by Fast Retailing; Inditex, which owns Zara and Bershka; SMCP, the owner of the French fashion labels Sandro and Maje; and the footwear company Skechers.

Revealed by the investigative website Mediapart, the investigation follows a complaint filed in early April by campaigners including the anti-corruption group Sherpa, the Uyghur Institute of Europe and a Uyghur who was interned in Xinjiang.