Beijing police have detained 54 people on suspicion of registering hospital appointments and illegally selling them to genuine patients at highly inflated prices.

The arrests came after a two-month investigation at five hospitals across the capital, including Peking University Third Hospital, according to a police statement on Monday.

Scalpers — known locally as huangniu, or yellow bulls — have long been a problem for China's health system, as they often mean lengthy waiting times for patients unwilling to pay their exorbitant prices.

Depending on the experience of the doctor, the cost of booking a hospital appointment is usually under 100 yuan ($15). The scalpers caught in Beijing were selling appointments for as much as 2,000 yuan, according to the police.

"These scalpers came from six gangs," the police said, adding that they are also suspected to have abused online booking systems. "We took about two months to break the case, and we'll pay high attention to such scalpers and launch a campaign against them."

The statement added that 37 of the suspects had received administrative detention, an extrajudiciary punishment that can last up to 15 days, while the others are awaiting criminal prosecution.