Despite Apple’s input, higher salaries and reduced overtime, China’s Foxconn factories are still mistreating their employees, suggests new research.

The Guardian reports that the Hong Kong workers’ rights group Students and Scholars Against Corporate Misbehaviour (Sacom) has interviewed 170 workers and supervisors at Apple supplier Foxconn’s factories across China, revealing that intimidation, exhaustion and labour rights violations “remain the norm” there.

The interviews were carried out between March and May this year at the Shenzhen and Zhengzou factories, and revealed that workers are still suffering in the plants that manufacture Apple products such as the iPhone and iPad.

Workers told Sacom that they had been made to clean toilets, sweep lawns and write “confession letters” as punishments.

Up to 30 workers are sharing each dormitory on campus, with eight sharing a room, and any electrical items like kettles or laptops will be confiscated by Foxconn.

A select few workers are now allowed to have a stool to sit on, rather than being forced to stand, however Sacom claims that these workers are told to sit on a third of the seat in order to remain “nimble” while working.

According to the Shenzhen regional public register, 728 industrial injuries were reported at Foxconn factories in the city since Mat 2011, but Sacom thinks that not all injuries are reported of officials. “The management simply negotiate with the injured workers for a settlement,” reports Sacom. “According to the respondents, cases of industrial injuries have an impact on the annual bonus received by middle management. Therefore, the middle management are very reluctant to report all the cases.”

This week, we reported that Foxconn’s CEO Terry Gou has promised to double wages for workers at his factories by 2013.

Earlier this year, journalist Rob Schmitz became the second journalist to be granted access to Apple production lines in Chinese Foxconn factories, following the revelation that Mike Daisey, an author and actor who accused Apple of ill-treating its factory workers, had fabricated some of his reports.

On Wednesday, Daisey criticised Kara Swisher and colleague Walt Mossberg for not being tough on Tim Cook at their D10 interview.