A China factory that has produced shoes for the Ivanka Trump brand and other US companies is the worst labour rule violator among dozens of similar production plants checked by undercover investigators, an advocacy organization said. Workers at the Huajian factory in Jiangxi province typically put in 15-hour days, with just two days off each month, according to a report by China Labour Watch, a group that since 2000 has investigated workplace conditions at Chinese plants that supply many of the world’s best-known companies and brands. Workers assigned to produce shoes for Easy Spirit’s brand were forced to remain at work until 1.30 am making changes in late May after a representative of the US company complained that the manufacturing work was of “inferior quality”, the report said. Chinese labour activists investigating Ivanka Trump supplier held for ‘stealing industrial secrets’ The factory’s employees were verbally and sometimes physically abused and had to wait until late April to receive payment for hours they worked in March, the report said. Additionally, the workers were paid roughly US$352 for 350 monthly work hours, below what China’s labour law stipulates, the report added. Along with producing shoes for the Trump brand and Easy Spirit, the factory has done work for such well-known US companies as Marc Fisher Footwear, Nine West, Karl Lagerfeld, Naturalizer and Guess, the report said. Nonetheless, the factory “is the worst among the dozens of factories we have investigated over the past year”, the report concluded. Factory representatives could not be reached for comment. Three undercover investigators for China Labour Watch who checked the production centre and interviewed workers in March or April disappeared in May and are believed to have been arrested by the Chinese authorities. “We urge China to release them immediately and otherwise afford them the judicial and fair trial protections to which they are entitled,” Alicia Edwards, a US Department of State spokeswoman, said in a statement earlier this month. China has rejected calls for the men’s release. “So far, we haven’t heard anything,” Li Qiang, the advocacy group’s executive director, said. He repeated previous entreaties for Trump’s company and other US manufacturers to help win the investigators’ release. China invites Ivanka Trump and Jared Kushner to Beijing, sources say Trump removed herself from day-to-day involvement with her brand in January. Her spokeswoman did not respond to an email seeking comment. In a written statement, Ivanka Trump President Abigail Klem said the company’s shoes had not been produced at the factory since March. “Our licensee works with many footwear production factories and all factories are required to operate within strict social compliance regulations,” the statement said. Marc Fisher, Trump’s footwear licensee, said it “does not comment on its business procedures or strategies”. Other companies cited in the China Labour Watch report did not respond to emails seeking comment.