The 'circumcisions' were done after a 'health investigation of genitals campaign' organised by the Chongqing Naturopathic Research Society - an organisation under the official Chongqing Association for Science and Technology.

However, the association stressed that the naturopathic research society was not authorised to perform surgeries.

The newspaper said schoolboys from a grade three class at Hope School were suddenly told to stay for a genital check-up. Two men from the society who claimed to be doctors ordered them to drop their trousers.

A few days later, some of the boys received notices from the 'doctor' saying they needed to be circumcised or they might become sterile or suffer penile cancer.

As a result, the families of the boys paid 180 yuan each to have a circumcision done by a 'doctor' named Zhao at a birth control facility, the newspaper said. One boy, Xiaojin, dropped his pants and his penis was grabbed by Zhao, who sprayed something and then kneaded it until the boy cried out. An unnamed drug was then smeared on it.

One villager whose son, 8, received the notice, said: 'I didn't let my son have such an operation because I took him to see another doctor,' said the villager, who identified himself only by the name Luo.

'My doctor said it was too early for a boy to undergo such a surgery. I would only allow my son to have such important surgery in a big hospital.'

The municipal health department said it was shocked by the parents' complaints. Four experts were sent to the town to follow up on the victims, and all medical treatment was provided free.

County government, police and the supervision office were all investigating.