BEIJING - Over 36,000 cases were investigated and more than 17,000 suspects detained during the first 45 days of a nationwide crackdown on illegal food production, gambling, drug trafficking and other offenses, according to public security authorities.

A statement issued on Friday by China's Ministry of Public Security summarized the "preliminary progress" of the campaign, stating that 7,165 venues used for illegal activity have been shut down so far.

The statement also mentioned a group of cases concerning the manufacture and sale of clenbuterol, an illegal fat-burning drug that is sometimes illegally used as an additive in pig feed, and "gutter oil," or reprocessed cooking oil that is illegally produced using waste oil from restaurants.

The statement also highlighted police officers' attempts to gather tips from the public through phone calls, e-mails and microblog posts. Over 28,000 tips were received and more than 9,200 of them were confirmed to be accurate, according to the statement.

The campaign was launched on August 22 to eliminate illegal food producers and vendors, factories producing counterfeit goods and markets built for the disposal of stolen goods, pornography, gambling and drug trafficking.

The ministry did not specify the ending date of the campaign in its statement, but described it as a "long-term" task.