Major fashion brands have been linked to viscose produced in polluting factories, according to a new report by the Changing Markets Foundation.

Viscose, touted as a sustainable alternative to cotton or polyester, is often used as a cheaper and more durable alternative to silk, commonly in skirts and dresses. Experts say it is just as likely to be found in a £10 t-shirt as a £2,000 suit.

Investigators for the Changing Markets Foundation visited 10 manufacturing sites in China, India, and Indonesia, and found severe environmental damage including water pollution from untreated contaminated waste, and air pollution. Brands alleged by the report to source from these factories include H&M, Inditex (the owner of Zara), Marks & Spencer and Tesco.

Most of the brands contacted by the Guardian have acknowledged that the impacts of viscose production are an industry-wide problem and say they are exploring ways to produce more responsibly.