A syringe in a taxi that pierced a man's skin on Aug 21 had fluid that tested positive for HIV antibodies, Beijing city police confirmed on their micro blog on Monday.
"The city's center for disease control and prevention and its counterpart in (Chaoyang) district tested the unidentified fluid in the syringe," the police said.
Police also confirmed that a man reported to police on the evening of Aug 21 that he was hurt by the syringe.
Police said they have created a special team to investigate the case.
"We request citizens to provide clues and assist police. People who have information can call 110," police said.
The victim, who took a taxi in Haidian district in Beijing, was injured by a syringe on the back of the front seat.