Police are investigating Dana Hyeondae Clinic over a massive hepatitis C infection caused through syringe recycling, as well as other allegations of medical misconduct.
Investigators from Yangcheong Police Station in southwestern Seoul raided the hospital to seize medical equipment including syringes; as well as a list of patients, Wednesday.
Three workers were questioned and some of them admitted the reuse of syringes, which caused the hepatitis C outbreak, police said.
According to the Korea Centers for Disease Control and Prevention (KCDC), a total of 78 among 2,268 patients who visited the clinic since 2008 have tested positive for hepatitis C as of Thursday after receiving intravenous injections there.
Other allegations have emerged about the clinic with police suspecting it used some 10 medications containing diuretics and steroids on patients under the name of "diet injections" which help people lose weight.
A patient told police that she suffered serious side effects after having an injection at the hospital, losing 3 kilograms a day.
It was found earlier that the doctor's wife practiced medicine without a license on behalf of her husband who suffered brain damage following a car accident in 2012.
The doctor has been in an improper condition to continue practicing due to a speech impediment and hand tremors.
Yangcheon Health Center filed a complaint with police against the doctor and his wife for violating the Medical Law. Police said they will summon the couple after reviewing the seized resources.