The ongoing investigation into the death of a 29-year-old Beijing man who was found dead in police custody has seen a new development. Authentication conducted by People’s Procuratorate of Beijing Municipality confirmed that Lei Yang died of suffocation caused by inhalation of gastric contents into the respiratory tract.

According to the Procuratorate, misconduct of involved police officers is confirmed. Xing, deputy chief of a sub-branch under Beijing Changping district police and one auxiliary police officer surnamed Zhou have been arrested for duty negligence.

The People’s Procuratorate of Beijing Municipality formed a forensic team of top-level forensic and pathology experts to authenticate the preliminary autopsy results on Monday. Family members of Lei and involved police officers as well as their legal counsels have been informed of the authentication results.

The Lei Yang case took place on May 7. On that night, Lei, who graduated with a master's degree from the prestigious Renmin University, died after police raided a foot massage parlor that was alleged to be hosting prostitution. Investigations were done after Lei’s family raised doubts about the official police story, and the autopsy was started on May 13.