Environmental groups in China have criticised Apple for a lack of regard for its Chinese suppliers, blaming the Cupertino company for poor environmental and work safety standards.
Reuters reported this week that the Institute of Public & Environmental Affairs (IPE) published a critical report on the Apple supply chain, accusing the company of only caring about the "price and quality" of its products.
"We've found that Apple isn't honouring its commitment in ensuring its supply chain's work safety and environmental responsibility and giving dignity and respect to the workers," Ma Jun of IPE told Reuters.
"In some ways they drive the suppliers to cut corners to win their contracts."
In response, Apple said that its own supplier responsibility reports "document the progress of our extensive auditing programme since 2006".
A spate of suicides at Foxconn's campus in Shenzhen last year were blamed on working conditions but Apple strongly denied this.
The use of N-hexane at a plant in Suzhou, a toxic substance banned in many countries, caused controversy in January 2010 and IPE claimed that at least 47 workers in the factory, which makes LCD screens, fell ill.