The 18-year-old had allegedly sustained multiple injuries, and the centre's director and staff members have been held by police, according to reports.
The incident took place earlier this month in eastern Anhui province.
China has seen a proliferation in so-called "boot camps" aimed at treating internet and gaming addictions.
Some are known for their military-style discipline and have been criticised for overly harsh practices.
'Completely covered with scars'