BEIJING — The tendency by some police officers to view condoms as evidence of prostitution is hindering their use among sex workers and undermining efforts to prevent the spread of H.I.V. in China, a report has said.

The report, published Tuesday by Asia Catalyst, a nonprofit organization based in New York, surveyed or interviewed more than 500 male, female and transgender prostitutes in three major Chinese cities, and it found that they were significantly less likely to carry or use condoms if the police had questioned them in the past.

Sex work is illegal in China, and condoms have been categorized as a “tool of offense” in the Ministry of Public Security’s guidelines for prostitution cases. Condoms can be a deciding factor in whether to arrest prostitutes or hand down penalties, the report said.

“Law enforcement actions are having a profound effect on sex workers’ health and safety, including on condom use and behaviors,” said Karyn Kaplan, the executive director of Asia Catalyst. “Sex workers are more likely to agree to client demands to not use condoms, reduce the number of condoms they carry or try various methods to hide condoms.”