New research released this week has linked international fashion brands to a textile plant in West Java that is accused of dumping industrial wastewater containing a cocktail of toxic and hazardous chemicals into a local river.

Greenpeace International has connected the Gap, Banana Republic and Old Navy brands to PT Gistex Group, the company behind the polluting facility, along with Brooks Brothers, Marubeni Corporation, Adidas Group and H&M.

However, US-based retailer Gap Inc has told just-style it does not source from the PT Gistex textile division referred to in the report.

The facility is located near Bandung in West Java - where Indonesia's modern textile industry is concentrated - and undertakes polyester weaving and wet processing such as dyeing, printing, and finishing of polyester.

The research, 'Toxic Threads: Polluting Paradise,' describes how the PT Gistex unit has taken advantage of a system that requires little transparency about its activities and where inadequate laws are failing to prevent the release of hazardous chemicals.

A wide range of hazardous substances - including nonylphenol and tributyl phosphate - were identified in the water samples taken from the PT Gistex facility's discharge outfalls.

Many of these chemicals are toxic, while some have hormone-disrupting and highly persistent properties. The investigations also revealed wastewater from one of the smaller outfalls to be extremely alkaline or 'caustic', indicating that this wastewater had not received even the most basic treatment before discharge.

Greenpeace is now calling on the fashion firms "to work with their suppliers in Indonesia and elsewhere to urgently eliminate all uses of hazardous chemicals from their supply chains and products."

So far more than 17 international brands and retailers including Levi's and Zara have committed to its Detox campaign to achieve zero discharge of all hazardous chemicals by 2020.

They have also agreed to work with their suppliers around the world to disclose all releases of hazardous chemicals from their facilities to communities at the site of the water pollution.

The textile industry is currently one of the major contributors to industrial toxic water pollution in West Java, with 68% of industrial facilities on the Upper Citarum producing textiles.

Gap Inc says it has reiterated to PT Gistex's parent company the importance of adherence to its Code of Vendor Conduct.

"All vendors supplying finished goods to Gap Inc brands are required to adhere to our Code of Vendor Conduct that helps to ensure our branded products are made responsibly, and that vendors adhere to Gap Inc product requirements and chemical restrictions," a statement said.

"Reducing environmental impact is important to Gap Inc, and we work on this issue at the laundry, mill and manufacturing levels.

"We support a water quality programme, requiring that the wastewater from denim laundries be properly treated before discharge. We have established best practices with mills to reduce the environmental impact of fabric dyeing and finishing. We also have a long-established product testing programme and use accredited independent third-party labs to test our branded products.

"We know that as an industry more needs to be done, and at Gap Inc we continue to evolve our sourcing practices."