An online outcry over the three-month police detention of a Chinese doctor for describing a domestic brand of alcohol as “poison” has highlighted the ability of companies to use criminal law to punish critics of their products.

Police from China’s Inner Mongolia region detained Tan Qingdong in January over an online post accusing the Hongmao Pharmaceutical Company, also based in Inner Mongolia, as falsely advertising its alcoholic products as medicine and referring to the drinks as “poison”. Police accused Dr Tan of causing Hongmao $223,000 in losses.

Dr Tan’s detention on suspicion of “damaging the reputation of a company”, punishable by two years in jail under China’s criminal code, became one of the most discussed topics on China’s internet when it came to light at the weekend, sparking a backlash from online commentators who said the charge was extreme.