GUANGZHOU -- An investigation is under way into an urban management official in South China's Guangdong province after muckrakers in cyberspace found he and his family members own 21 houses.

Cai Bin, a senior official with the Panyu District Branch of the Guangzhou Municipal Urban Management and Law Enforcement Bureau, is being investigated for corruption, Guo Xuanyu, spokesperson with the discipline inspection watchdog of Panyu told Xinhua on Wednesday.

The scandal emerged after netizens posted pictures of Cai's properties onto Sina Weibo, China's microblogging site.

"It is basically true that Cai has 21 houses according to our preliminary investigations," said Guo.

The number is much more than Cai previously declared to superior authorities.

Preliminary investigations found that Cai, 56, owned 18 houses in Panyu and three others in Nansha District at the mega-city of Guangzhou, Guangdong's capital.

Of the 21 houses, 19 are under the name of his wife Shi Liying and his son. One is jointly owned by Cai and Shi and the other is under the name of Cai.

Among the houses, with a combined floor space of over 7,200 square meters, are a 240-square-meter multi-storey house and a 3,405-square-meter factory building.

A real estate agency estimated that the total market value of the houses could be 40 million yuan ($6.3 million). Cai's monthly pay is around 10,000 yuan.

Cai is the latest in a number of Chinese officials who have been targeted by the country's netizens and later investigated by disciplinary watchdogs.

Other officials include one who was found having at least 11 expensive wristwatches and another who allegedly beat up an airline stewardess.