Local police said they could do nothing regarding conditions or pay because the factory has a labor contract with the Sichuan Civil Affairs Department.

According to Wang Yong at the county's Civil Affairs Bureau, there was no organiza-tion in the county registered as the Quxian Beggars Adoption Agency, adding that there was only one official relief station in the county aiming to help all types of vulnerable groups, including physically and mentally disabled people.

Zeng was previously been found to have engaged in human trafficking. In 2007, he was wanted by police in Leiyang, Hunan Province, in connection with a case in which he was found to have sold beggars to a brick factory in Leiyang where a beggar was tortured to death, the Legal Weekly re-ported.

Zeng, who remains at large, was said to have been previously praised by the local government in Sichuan for "his success in solving the issue of beggars," according to the report.

Cases involving mentally disabled people being sold and used as forced laborers have been reported throughout the country.

In 2006, police in Zhengzhou, Henan Province, arrested Zhou Jinghuan, a local woman, who was found to be selling around 1,000 people a year to brick factories or mines in the province for 170 yuan each, to be used as forced labor, CCTV reported. Most of the people she sold were beggars or mentally disabled.

Dong Baohua, a Shanghai-based lawyer, told the Global Times that there were laws on the employment of the disabled people to safeguard their labor rights, the laws set up only "overall" principles.

"The existence of a labor agreement is by no means a sound reason for the police to stop further investigation, because the labor agreement does not give the factory the right to mistreat the workers," Dong said.

Dong also suggested that the Disabled Persons Federation enhance its relations with legal aid organizations to better help the disabled who are vulnerable to labor traffickers.