Yes. On August 8th, 1985, there was 8 pieces of human remains found on a beach in Macau. After a couple days 3 more pieces were found. Police believed at least 4 victims were involved. They suspected that sharks were responsible for the death. The investigation did not show any progress until 8 months later, when the police received a letter of reporting 10 missing persons (included the owner of Baat-Sin restaurant and his family members of 8, plus 1 hired worker). Following the leads the police arrested a suspect named Wong Chi Hang, whom was subsequently charged with murders of 10 and put in custody. But before the trial day Wong committed suicide in the jail on October 4th, 1986.
The media wildly reported that Wong had sold the pork-chop buns that were made with the victims' body parts (instead of pork meat). But it has never been able to confirm such a rumor. The mystery of "human pork-chop-bun" has become one the most known and discussed crime stories in Macau, Hong Kong and GuangDong.
Anthony Wong, who portrays Wong Chi Hang, won the Best Actor of the 13th Hong Kong Film Award back in 1994.