Some 48 apparel brands and retailers including H&M, Nike, Wal-Mart, Levi's, Adidas, Gap and Marks & Spencer have been accused of purchasing clothing from suppliers who illegally discharge polluted water in China.

Chinese environmental campaigners also listed Tesco, Li Ning, Polo, Tommy Hilfiger, Zara and JC Penney as among those who buy products from Chinese textile firms with illegal discharge records.

The report, produced by Friends of Nature, the Institute of Public & Environmental Affairs (IPEA), Green Beagle, Envirofriends and Nanjing Greenstone, noted more than 6,000 environmental violations by Chinese textile enterprises.

The data, recorded in a China Water Pollution Map compiled by the IEPA found problems including secret discharge pipes, direct wastewater discharge, improper use of wastewater treatment facilities, and pollutant discharge amounts in breach of authorised standards.

China's textile industry accounts for half of the global total, while its fabric and apparel exports have a 34% share of world trade. However, the textile industry produces close to 2.5bn tons of wastewater and other pollutants annually, which pollute rivers, lakes, the atmosphere and the oceans, even the soil and groundwater.

The report found the amount of wastewater discharged from dyeing processes accounted for 80% of the textile industry's total wastewater discharge and contains a number of harmful substances. Additionally, the re-use of water in the textile industry lags way behind that of many other industries, "creating a situation where water efficiency is incredibly low".

The environmental groups are calling on the companies included in the report to investigate their supply chains and make greener purchases.

They also see collaboration as key to overcoming the textile sector's pollution problems, including stronger government supervision, greater transparency of information, pressure from apparel brands and retailers on their suppliers to reduce pollution emissions, and "a sense of environmental responsibility" within the textile industry.

The research follows similar investigations by Greenpeace last year, which also found clothing suppliers in China were releasing a cocktail of chemicals into the Pearl and Yangtze River deltas.

As a result of the subsequent global 'Detox' campaign, six leading brands and retailers - Adidas, C&A, H&M, Li Ning, Nike and Puma - have all agreed to work together to achieve the goal of zero discharge of hazardous chemicals in their supply chains by 2020.