Police investigation of the alleged propofol abuse by Hotel Shilla CEO Lee Boo-jin gathered steam, with the head of a plastic surgery clinic in Seoul where she is claimed to have taken the injections was booked without detention Friday.

The clinic, located in Cheongdam-dong, is suspected of having administered the highly addictive anesthetic injections in 2016 to Lee, daughter of Samsung Group patriarch Lee Kun-hee.

The police booked the doctor on charges of violating the medical law and raided the clinic as he refused to submit the medical chart and records, the police said Sunday.

During the raid which took place over the weekend, the police is reported to have obtained the medical charts, records of drugs used and other documents from the clinic’s computers.

The police will look closely into the records to discover if propofol was used in violation of regulations and whether Lee had abused the substance during the treatment she received there.

However, the investigation may face difficulties as the records of drugs used were handwritten until May 2018, and the records from 2016 might have been discarded. The law requires such records to be kept for two years.

For now, it’s unclear if Lee continued to receive treatment at the clinic after 2016.

The police also said that they questioned the nurse’s assistant who first made the allegations of Lee’s propofol abuse during an interview with an online news outlet.

The assistant, who worked at the clinic from January to October 2016, claimed that Lee visited the clinic at least twice a month and received propofol injections at a VIP room.

The assistant also said the clinic fabricated the records of drugs used to conceal her propofol abuse.

The Samsung scion on Wednesday said she went to the clinic for surgery and treatment, but denied the allegations of propofol abuse.

The police said they would check if Lee’s explanation is in accord with the medical records they obtained in the weekend raid.

The doctor’s call history may be checked, if necessary, as the assistant claimed that Lee made appointments for the treatment by personally calling the doctor, the police said.

Korean National Police Agency Commissioner General Min Gap-ryong on Monday told reporters that the investigation would not take long, as the police has already secured records from the clinic.

By Park Ju-young (jupark@heraldcorp.com)