Luxury fashion houses Dior, Chanel and Dolce & Gabbana are among the least transparent of the major retailers when it comes to providing information about their supply chains, according to an index ranking commitments to tackle slavery and forced labor.
The index, released on Monday by advocacy group Fashion Revolution, coincided with the fifth anniversary of the Rana Plaza factory collapse in Bangladesh, where 1,135 garment workers were killed and more than 2,000 were injured.
The collapse of the eight-story building on the outskirts of the capital Dhaka on April 24, 2013 sparked demands for better safety in the world's second-largest exporter of ready-made garments.
"We want to see the fashion industry respect its producers ... to foster dignity, empowerment and justice for the people who make our clothes," said Orsola de Castro, co-founder of Fashion Revolution.
Sportswear giant Adidas and its subsidiary Reebok topped this year's Fashion Transparency Index, followed by another sporting label Puma and Swedish fashion group H&M.
While many brands indicated a greater willingness to be transparent about their supply chains, the report said more was needed.
None of the 150 retailers scored higher than 60 out of 100, the index said, which assessed factors like company policies, supply chain transparency, and their commitment to improve conditions for factory workers.
"Greater transparency means greater scrutiny and accountability. It means exploitation has fewer places to hide," said Peter McAllister, head of the Ethical Trading Initiative, a global group that aims to improve labour conditions for workers.
"Unfortunately, many businesses are yet to even start their journey, and for these companies we hope the report will be a much-needed wake up call. They can and must do better," he said in a statement.
Some of the lowest-ranking firms - including Dior, Dolce & Gabbana and Max Mara, all of which scored zero points on the index, and Chanel and Longchamp, which scored three points apiece - did not respond to requests for comment.
Spanish brand Desigual, which also scored zero points, said all of its suppliers must comply with its code of conduct, which will be published online in the coming weeks.
Suppliers that breach the code are "disqualified to work with Desigual immediately and permanently," a spokeswoman told the Thomson Reuters Foundation in an emailed statement.
In the wake of the Rana Plaza disaster, nearly 200 clothing brands and retailers from over 20 countries became signatories to the legally-binding Bangladesh Accord.
Accord inspectors have carried out inspections of more than 1,800 factories, identifying over 118,500 fire, electrical and structural hazards, unions said.
"Textile workers across the world are producing our clothes in some of the most dire conditions," said Danielle McMullan, a researcher at the Business and Human Rights Resource Center, a U.K.-based rights group. "Transparency from brands is a crucial step to improve standards and protect workers."
