The 25-year-old employee is said to have misplaced one of the devices; and after searching the factory, he reported it missing to his boss. Sun Danyong was then said to be subjected to unbearable interrogation techniques at the hands of Foxconn's Central Security Division.
Various publications say that Sun's apartment was searched, and that the young man was placed in solitary confinement and physically abused.
The Shanghaiist reports (and translates) that Foxconn has already issued a statement apologizing for the the investigative techniques used while trying to locate the missing iPhone and says the staff member responsible has been suspended without pay pending an internal investigation.
However, despite the Foxconn statement, officials who work with the staff member in question say that it's unlikely Sun was beaten because the security office is just one big room. With roughly 60 people working there, even if Sun was taken behind a screen, they would have heard something if he was abused.
Sun threw himself off of his 12th floor balcony on July 16, three days after he reported the phone missing.