Five police officers are being investigated over a high-profile case in which a man died in custody, Beijing prosecutors said on Wednesday.

Lei Yang, 29, who lived in the capital's Changping district, died on May 7 about an hour after he was detained on suspicion of soliciting prostitution.

Lei's family demanded an investigation to assess if he had been attacked by police. His wife and the family's lawyer requested the investigation into police officers and auxiliary officers involved in the case. The family also asked for a third-party independent autopsy on May 13.