Chinese authorities are able to retrieve deleted WeChat messages from a suspect’s phone to catch criminals, a government watchdog admitted on Monday in social media posts spotted by South China Morning Post. The stunning admission confirms what many have believed for years: WeChat can be used as a government surveillance tool, and even once-deleted messages can be retrieved by authorities.

WeChat’s parent company Tencent denied any wrongdoing, saying in a social media post, “WeChat does not store any chat histories — they are only stored on users’ phones and computers.” That stance is similar to one Tencent has taken in the past, when Chinese auto industry executive Li Shufu stated that the company’s CEO “must be watching all our WeChats every day,” at a business forum back in January. Tencent denied that claim as well, saying, “WeChat will not use any content from user chats for big data analysis” and “WeChat’s technical model does not store or analyze user chats.”

The anti-corruption watchdog, the Chaohu Municipal Discipline Inspection and Supervision Commission in eastern China, admitted in a social media post that it used deleted WeChat conversations from a suspect to figure out who else to question in a case. The watchdog said the suspects it questioned (who were all party officials) broke down and confessed to violating the rules. As a result, the commission was able to punish 63 party officials in total.

The commission’s post went viral over the weekend, but by Sunday, it had been taken down. The controversy caused a stir among Chinese web users for being a rare admission of user privacy violations on behalf of a Chinese-owned corporation. Many took other forums to question how they should protect themselves from having their private conversations read. Some wondered if physically destroying their smartphones might protect them from government eavesdropping. The discussions come at a time when most of the world is reconsidering tech companies’ user data retention policies and as Europe’s new data policies go into effect on May 25th.

Back in March, the Australian defense department banned WeChat from military grounds, saying the app did not meet defense standards, although it did not explicitly cite security concerns. We’ve reached out to Tencent for comment.