A full-page advertisement in a major Guangzhou newspaper imitating a woman gloating over an extramarital affair, but which is actually part of a cosmetic brand's campaign, stirred up heated debate and was canceled, with claims it is a challenge to social morality.

The advertisement, which looks like a letter, was printed on Tuesday in Southern Metropolis Daily, a major newspaper in the capital of Guangdong province.

The fictitious writer, who refers to herself as Mrs Zhang, asks Zhang's ex-wife to let him go and gives her advice on how to find her own Mr Right.

"Excellent men only belong to a woman who can present herself well. May you wake up as early as possible and learn how to best present yourself. May there be no mistresses anymore," the ad reads.

Fu Yisu, a public relations manager with Canton Fair E-commerce Co, said: "Is the newspaper promoting the success of a mistress? I was very surprised to read the ad. It poses a great challenge to traditional morality."

However, Li Hu, deputy market managing director of Southern Metropolis Daily, said the content of the ad had been carefully examined prior to its publication.

"Actually, it is a commercial ad, promoting a cosmetics brand. The content is in line with related advertising laws," Li told China Daily.

Li said the ad is part of a series to be printed over seven days.

A marketing manager at Nanfang Daily, which administers Southern Metropolis Daily, said on condition of anonymity that a South Korean cosmetics company signed a contract with the newspaper to print the advertising series.

"Newspapers, which have seen sluggish market performance in the last two years, sometimes have to attract readers and clients by printing such stunning ads," she said.

However, late on Tuesday, the provincial industrial and commercial bureau said it has ordered the newspaper and the cosmetic company to stop running the advertisement to prevent negative social impact.

The commercial violates the advertising law as it "violates good social conventions", it said.

Chinese newspapers' advertising revenue is expected to drop in the coming years, challenged by the increasing coverage of digital media, according to industry experts.

In 2011, the nation's online advertising revenue exceeded that of newspapers for the first time as more advertisers began looking to Web media platforms such as search engines, along with commerce and video websites, according to Beijing-based market research firm iResearch.

According to the China Advertising Association, Chinese newspapers' advertising revenue dropped 7.3 percent year-on-year in 2012.

Xie Liang, a veteran commentator with Radio Guangdong, said: "China's surging online advertising market has been a boon for advertising platform providers. But this time, the advertisement in Southern Metropolis Daily proved that traditional print media can still find the right clients by printing innovative ad content."

The ad quickly spread to Sina Weibo, China's biggest micro-blog platform, and WeChat, a mobile messaging application.