The operation, which involves breaking the patients' legs and stretching them on a rack, has become popular among young professionals desperate to climb up the ladder in the country's height-conscious society.

"Leg-lengthening surgery is a clinical orthopedic treatment, not cosmetic surgery," Mao Qun'an, the Health Ministry spokesman, said on Tuesday at a press conference.

"Leg-lengthening surgery must only be carried out for strict medical reasons and performed in authorized hospitals," Mao added.

The surgical procedure was originally developed in Russia to help patients with legs disfigured by accidents or birth defects such as dwarfism.

According to the Beijing Institute of External Skeletal Fixation Technology, the cost of the surgery is about 15,000 to 25,000 U.S. dollars and it takes about two years to recover.

Last month, ten people were reported to have been disfigured after they underwent the operation last year. They were all introduced to the Beijing Xiangshan hospital from a Chinese website that advocates "height surgery with no pain."

Hospitals must inform patients of the risks of the surgery and get the patients consent, Mao said.

Health departments at all levels must investigate medical institutions that illegally carry out leg-lengthening surgery and punish those without the right qualifications, he added.