The bereaved family of a patient who died at a psychiatric hospital run by psychiatrist Yang Jae-woong has claimed that police failed to conduct a proper investigation despite 21 minutes of CCTV footage going missing around the time of the death.

The mother of the deceased patient appeared as a reference witness yesterday (October 13) at a parliamentary audit of the Gyeonggi Nambu and Bukbu Provincial Police Agencies by the National Assembly's Public Administration and Security Committee.

The mother stated that her daughter was admitted to the hospital to treat an addiction to diet pills, but died in an isolation room just 17 days later.

In particular, she testified that for days before her death, her daughter complained of stomach pain and begged to be sent to an emergency room, but did not receive proper treatment.

The bereaved family also argued that there were flaws in the police's initial response.

The mother stated that immediately after her daughter's death, she requested CCTV footage from the hospital and received it 12 hours later, but a 21-minute portion during the early morning hours when her daughter was dying was missing.

She pointed out that despite this, the police only raided the hospital six months after the death.

The mother also claimed that the investigation was effectively suspended under the pretext of delays in the Korean Medical Association's review.

She added that while the police investigation was stalled, the National Human Rights Commission of Korea first confirmed the falsification of nursing records and illegal physical restraint carried out without a doctor's orders.

Criticizing the investigation process, the mother asked, "I want to ask what the police, who even conducted a search and seizure, have been doing all this time."

Lawmakers attending the audit also took issue with the police response.

People Power Party lawmaker Kim Yeji pointed out that if the police had secured electronic medical records and access logs immediately after the incident, they could have verified whether the records were altered, but instead neglected to do so.

Lawmaker Kang Myeong-gu of the same party similarly criticized the police for failing to properly investigate for six months and only belatedly resuming investigation after the Human Rights Commission's probe.

In response, Kim Hong-geun, Acting Chief of the Gyeonggi Nambu Provincial Police Agency, partially acknowledged shortcomings in the initial investigation regarding the failure to secure electronic records and other materials on the day of the incident.

Regarding calls for action against those responsible for the investigation, he replied that he would clarify the wrongdoings and then establish a stance.

Reported by Kim Minjeong | Video by Kim Kihyun | Graphics by Lee Jung-joo | Produced by SBS Digital News