Apple has been heavily criticised by human rights campaigners after a new undercover investigation shed light on numerous ethical violations in Chinese factories used to manufacture the iPhone 6s smartphone. The latest report from China Labor Watch (CLW) found that legal violations and dangerous working conditions that have been a black mark on Apple's supply chain for several years, are largely unchanged since the last investigation that was carried out in 2013.

The report, titled Something's Not Right Here, found that despite cases of workers dying and falling ill, adequate safety training and protective measures in line with Chinese law or Apple's code of conduct are still not met. The information was gathered by a CLW investigator working undercover at the Shanghai-based Pegatron Technology factory used by Apple in the production of its latest flagship smartphone.

"The results of this investigation suggest to us that despite enjoying ever-growing commercial success, Apple refuses to do what's necessary to ensure workers who make that success possible are treated fairly and work in safe environments," Kevin Slaten, program coordinator at CLW, told IBTimes UK. "We can only conclude that Apple pursues profit maximisation for itself and its shareholders no matter the lives of people making Apple products."

Listed among the human rights violations are unpaid labour, unreasonable fines, 12-hour shifts six days a week and unhygienic living conditions. In order to cover up some of the more severe infringements, the report claims that Pegatron uses fraudulent documentation.

One of the biggest threats to worker safety, according to the report, is the lack of training on the handling of toxic chemicals. Workers at the factory are said to receive a list of hazardous substances − including arsenic, hexavalent chromium and mercury − but no further information is given about the way these chemicals are used at Pegatron.

The report's title comes from a quote from Apple CEO Tim Cook, who said in an interview last year: "One of the best ways you can make sure that things are happening well is if people stand up and say, 'Something's happening that's not right here'."

Cook went on to say: "We've audited so deep in our supply chain. We do it constantly, looking for anything that's wrong, whether it's down to the 'there's a safety exit blocked'. We have gone beyond the auditing and are now essentially holding university-style classes on the manufacturing campuses with our partners."

CLW's report reveals that the investigator was never told the location of an emergency exit while working undercover at the Pegatron factory, nor was he able to even locate an emergency exit.

"CLW's newest investigation reveals 23 categories of legal and ethical labour rights violations at Pegatron Shanghai," the CLW report states. "CLW has previously detailed how Apple has the greatest control of working conditions among all actors in its supply chain.

"It is not a question of whether Apple must ensure that workers making its products enjoy fair and safe working conditions. It is only a question of when Apple will make good on its commitments."

Apple had not responded to a request for comment from IBTimes UK on the report's findings at the time of publication.