Family members questioned what Foxconn Technology Group believed a sudden death of an employee at a plant in south China.
Ma Xiangqian, 19, was found lying dead near the stairway of company dormitory in Guanlan town, Shenzhen, at 4:30 a.m. on Jan. 23.
Ma's elder sister Ma Hui urged an open, recorded anatomy of her brother's body when journalists were at the scene.
A second forensis examination showed her brother died of unknown reasons, she said.
Ma Hui said she found big wounds in her brother's head and also bloodstains around the mouth and noses. She also had no idea of the whereabout of Ma Xiangqian's mobile phone.
The signs made her believe that her brother died of abuse or beating, she said.
Foxconn, a unit of Taiwan electronics giant Hon Hai, is offering a 500,000-yuan (73,219 U.S. dollars) reward for information on the worker's death.
Chen Hongfang, director of Foxconn's labor union office, late Wednesday refuted local media report that Ma was assigned to cleaning toilets after damaging equipment.
Ma had not shown up for work since Jan. 20, Chen said.
Li Jinming, Foxconn administrative general manager, said he would not comment on Ma Hui's remarks on the wounds and bloodstains as the company has not received report of the second forensis examination.
Li added that a company investigation found no evidence of unfair treatment of Ma Xiangqian.
Ma, from central China's Henan Province, started working at Foxconn in November 2009.
Foxconn, set up in 1988, has more than 700,000 employees worldwide and is the foremost provider of joint-design, joint-development, manufacturing, assembly and after-sales services to global computer, communication and consumer-electronics companies.
Another Foxconn employee in Shenzhen, Sun Danyong, committed suicide on July 16, 2009, during an investigation into the loss of a prototype of Apple's iPhone.
Foxconn reached a compensation deal with Sun's family. Foxconn made a one-off payment of 360,000 yuan (52,718 U.S. dollars) to Sun's parents and also pays 30,000 yuan annually to support them.