HANGZHOU - The clock may be ticking for another senior official whose suspiciously pricey watch collection has been exposed online just months after an almost identical case brought down one of his peers.

Yuan Zhanting, mayor of Lanzhou, provincial capital of Gansu, faces a corruption investigation after being pictured wearing watches that appear to be worth more than could be afforded on a legitimate public servant's salary. If the allegations prove true, he could be dismissed from his post.

Muckraking netizen Zhou Lubao on Monday posted a series of photos of Yuan wearing timepieces including a Vacheron Constantin worth about 200,000 yuan (31,746 U.S. dollars), an Omega of about 150,000 yuan and a gold Rolex. Their release triggered an instant public outcry for a probe into the official.

The Gansu Provincial Commission for Discipline Inspection confirmed with Xinhua on Wednesday that it has started an investigation to look into the allegations against Yuan.

Zhou, a company salesman in Haining, in east China's Zhejiang Province, told Xinhua in an exclusive interview that he began to follow news about Yuan about three months ago, when the mayor was reportedly related to a petition case.

"When I looked through news pictures of Yuan on the Internet, I unintentionally found that the watches he was wearing looked pricey," Zhou said.

After collecting a number of such pictures on the Internet, Zhou forwarded them to friends, who confirmed the brands and values of the watches, he said. The netizen also sent the pictures to a "watch expert," who supported the high value of the watches, based on the pictures.

Zhou then released the pictures through blogs and microblogs or placed them on forums on Monday, explaining, "I posted these pictures in more than 200 forums so as to attract as much attention as possible."

The pictures went viral overnight. Zhou's post on Sina Weibo, the popular Twitter-like microblogging service, has become one of the most discussed topics, logging nearly 6.5 million comments within days.

"How dare he wear such pricey watches in public after Yang Dacai was sacked for the same reason?" asked an Internet user with the screen name of "Buweiwu."

Yang, a work safety official in the northwestern province of Shaanxi, was dismissed from his post in September after Internet users compiled photos of him wearing luxury timepieces that he would have been unable to afford on his above-board earnings.

Internet user "Zhang Xiaohuan" said in a Weibo post that he had sent a request to the Gansu Provincial Information Office and the Lanzhou Municipal Finance Bureau, demanding that Yuan's salary in 2011 be made public.

Other Internet users, however, are suspicious about the motives of Zhou, criticizing him for trying to gain fame in the name of fighting corruption without solid proof.

Internet user Carissa said Yuan, a graduate of electronics information, used to work in college and scientific institutions before he became a politician about a decade ago, indicating that he might have had enough wealth for the expenditure on luxury watches.

"I hope the investigation results are revealed soon so the public can know the truth," said "shimenzideyu" on Sina Weibo. "I personally wish that all the watches he wore are fake and worth nothing so that we can still have some hope for officials."

Weibo user "Buyaonichengzhiyaonicheng" added, "It is woeful that China's anti-corruption efforts relies on Internet users."