A total of 25 people from the Chinese media sector have been arrested for an alleged scam in which suspects collaborated to extort money from companies in return for favorable coverage.

The No. 1 Branch of Shanghai Prosecution Service arrested Liu Dong, president of 21cbh.com, and Zhou Bin, deputy editor-in-chief of the website, on charges of suspected extortion, forced transaction and graft.

They were arrested alongside other media executives, including Money Week publisher Xia Ri and its chief editor Luo Guanghui, as well as Xia Xiaobo, who was in charge of a branch of 21st Century Business Herald in central China's Hunan Province.

In late September, Shanghai's public security bureau announced on a Sina Weibo microblog that they had detained Shen Hao, publisher of 21st Century Business Herald, and its general manager Chen Dongyang with the assistance of police in southern China's Guangdong Province.

The two were caught alongside the publication's editor-in-chief, surnamed Liu, as well as two other sales personnel.

Earlier, eight media personnel had been detained, including members of 21cbh.com, as well as heads of two PR firms, on suspicion of extorting money from more than 200 companies in return for favorable coverage on the site.

21cbh.com is run by Guangdong-based 21st Century Media Co., Ltd., which claims on its website to be "the largest professional media operator in the Chinese financial and business media industry."

The company's publications include 21st Century Business Herald, Money Week and 21st Century Business Review.

Under regulations set by the State Administration of Press, Publication, Radio, Film and Television, which manages the practices of all journalists in China, press credentials will be revoked in cases where media organizations have acted illegally.

Chinese authorities have been stepping up a crackdown on extortion in the media and paid-for news.

They have discovered problems such as press cards issued to people who are not journalists and newspaper websites contracted to advertising or PR agencies.