Chinese police are investigating a bootcamp for Internet addicts after a teenage boy died, apparently following a severe beating, just hours after checking in, the official Xinhua news agency said late on Wednesday.

Four trainers from the camp were detained in connection with 15 year-old Deng Senshan's death, after injuries were found all over his body, Chinese media quoted local government officials as saying.

China has the world's largest Internet population, with almost 300 million users at the end of last year.

Problems caused by Internet over-use are on the rise, especially among young Chinese seeking an escape from the heavy burden of parental expectations, and there are over 200 organizations offering treatment for Internet disorders in China.

Many of the camps are imbued with a military atmosphere. Patients are forced to replace hours in front of the computer with arduous physical drills or even more extreme treatments.

China in July banned electro-shock therapy as a treatment for Internet addiction after media reports about a controversial psychiatrist who administered electric currents to nearly 3,000 teenagers.

The market of Internet addiction treatment in China is in a total mess due to lack of diagnostic standards and treatment guidelines, Xinhua quoted Tao Ran, director of the country's first Internet addiction clinic, as saying.

The tragedy is not accidental. Most rehab camps adopt military training, but many teenage Internet addicts cannot handle it well. Thus it comes with conflicts and violence.

(Reporting by Emma Graham-Harrison)