A former bank official, given the nickname "House Sister" for owning 41 apartments in Beijing, has been taken into custody by police in northwestern China's Shaanxi province.

Gong Aiai, 49, former vice-president of Shenmu Rural Commercial Bank, was detained on Monday on suspicion of forging official documents and seals, Xinhua News Agency reported on Tuesday.

The Beijing Public Security Bureau said last week that Gong has 41 houses in Beijing, with a total area of 9,666.6 square meters. Previous investigations found Gong also had two houses in Xi'an, capital of Shaanxi province, and two in Shenmu county covering 600 sq m.

Ten of her houses and a car, an Audi, in Beijing were bought under an illegally registered hukou, which police seized on Jan 24, Beijing police said.

Hukou is a household registration system, on the basis of which, personal IDs can be issued. A person can have only one hukou, but police found Gong had four.

The Shenmu Rural Commercial Bank is a business and Gong is a long-term employee, not a civil servant, Xinhua reported.

Gong tendered her resignation in June and the bank approved this last month, Yu Qingcai, chairman of the bank, said in previous news reports.

Chen Tao, a lawyer from Beijing Lawyers' Association, said people convicted of forging official documents and seals might be sentenced to less than three years' in jail.

The imprisonment term could be lengthened to 10 years if the situation is deemed serious, he added.

That Gong managed to register four hukou has prompted public concern over management of the system.

Hong Daode, a law professor at China University of Political Science and Law, said public security authorities should tighten the regulation of hukou information.

"Citizens' hukou information should not be changed without official permission," he said.

Dai Peng, director of the criminal investigation department of People's Public Security University of China, said the hukou system should be reformed as soon as possible.

"The hukou is related to how people purchase property, job opportunities, medical services and education, which has caused unfairness between developed and less-developed regions," he said.

The case is a wake-up call to police authorities to improve supervision and stamp out abuse of power, he added.

Zhang Hongqiang, a press officer at the Ministry of Public Security, said police officers involved with illegal hukou registration will be punished.

"We should learn lessons from the case (of Gong Aiai) and improve the social management system," he said.

A policeman from Tieling Public Security Bureau in Liaoning province said Gong's case has highlighted hukou regulations. "Previously we held a meeting every week, but now we have two meetings to improve disciplinary management," he said.

In a separate case, an anti-graft body and related government departments in Shanwei, a coastal city in eastern Guangdong province, are investigating a senior police officer who was reported by a local business tycoon as having 192 houses.

"Zhao Haibin, member of the CPC committee of Lufeng city bureau of public security, was reported to own the large number of houses under the name of his company and himself in the cities of Shanwei, Huizhou, Shenzhen and Zhuhai. It will take time to investigate the case to its fullest extent," said an official from the Party discipline inspection commission of Shanwei's public security bureau.

It has been confirmed that Zhao, born in the 1950s, has two identity cards and he used the fake identity card to do business in recent months, said the official who did not reveal his name, on Tuesday.

Police in Zhuhai have withdrawn Zhao's fake identity card which was in the name of Zhao Yong and registered in the Xiangzhou district of Zhuhai, bordering Macao.

Zhao's real identity card was registered in Donghai township in Lufeng, a county-level city administered by Shanwei.

Zhao admitted having two ID cards, saying Zhao Yong is one of his other names.

Zhao said he applied for the fake ID card to do business in 1991 - before government departments introduced regulations banning officials' from having multiple ID cards. He denied having numerous houses, saying most of the houses are owned by the company run by his younger brother.

After a business dispute, Shanwei business tycoon Huang Kunyi accused Zhao of using his fake ID card to do business and acquire a number of houses.

Zheng Caixiong in Guangzhou contributed to this story.

Contact the writers at anbaijie@chinadaily.com.cn and zhangyan@chinadaily.com.cn