A crack down on the "hot issue list industry" on weibo was ordered by Shanghai's internet watchdog.

Shanghai's office for cyberspace affairs released an article on its WeChat account Wednesday condemning the industry for trading money for a prominent place in the "hot issue list", which it said was a "serious social issue".

The article was released after a weibo topic claiming Ziguangge – the official magazine of Chinese central government – used waste oils went on the hot list.

The topic was believed to be created and placed on the list by Chinese rapper PG One's fans, who mistook Ziguangge for a restaurant after the magazine and a dozen other media outlets criticized the rapper on social media over a 2015 track which features derogatory comments about women and references drug use.

The track was criticized by official Chinese media, including People's Daily and Xinhua News Agency.

The 24-year-old rapper, whose real name is Wang Hao, said that he will remove any inappropriate songs from the internet and promised to pay more attention to "positive energy" in his future music.

According to the article, the top three places on the list sell for 50,000 ($7,676) to 60,000 yuan, and the 10th to 20th places cost 35,000 to 45,000 yuan.