Shanghai police said they are looking for the source of a series of revealing photographs of a woman shot in downtown areas that have been posted online.

Several photos of a young woman appeared on the Internet during the National Day holiday earlier this month and on Wednesday. The pictures showed the woman lifting her skirt and raising her blouse on Hengshan road.

The pictures were taken at night and mosaics covered her more intimate parts.

A dozen pictures of what appeared to be the same woman were shot on the Bund and Xintiandi, also in the municipality’s Huangpu district, and were uploaded online on Wednesday.

Some psychologists said it might be commercial hype for a product or a sales pitch, and legal experts said the incident must be treated seriously and dealt with through legal channels.