The serious law violation case involving Bo Xilai, former member of the Political Bureau of the Communist Party of China (CPC) Central Committee, has been transferred to judicial organs, according to the CPC's Central Commission for Discipline Inspection (CCDI).

A total of 4,698 county-level cadres or higher-level cadres were punished by the CPC's discipline watchdogs in 2012 and 961 cadres at the county-level or above have been transferred to judicial organs, CCDI spokesperson Cui Shaopeng revealed on Wednesday.

Among them are Liu Zhijun, former minister of railways, Huang Sheng, former vice governor of east China's Shandong Province, and Tian Xueren, former vice governor of northeast China's Jilin Province. Their cases have been transferred to judicial organs, according to Cui.

Another two high-ranking provincial-level officials are under investigation for alleged discipline violations, Cui revealed.

Zhou Zhenhong, a former Standing Committee member of the CPC Guangdong Provincial Committee and head of the United Front Work Department of the provincial Party committee, was removed from office for suspected "serious discipline violations" in January last year.

Li Chuncheng was removed from the position of deputy secretary of the CPC Sichuan Provincial Committee for suspected "serious discipline violations" in December last year.

Nearly 73,000 people were punished for corruption or dereliction of duty in 2012, official figures released on Wednesday showed.

From January to November last year, discipline inspection and supervision authorities launched investigations into more than 11,000 cases in the construction sector, a hotbed of corruption.

Nearly 5,000 officials were found to have breached relevant Party discipline and laws in these cases, according to Huang Xiaowei, spokesperson with the Ministry of Supervision.

Among those officials, 3,780 received Party or political disciplinary penalties, while another 1,097 have been handed over to judicial authorities.

In the same period, discipline watchdogs uncovered 27,500 violations of regulations and laws involving land use and mine exploitation. Altogether, 3,891 people received Party and political disciplinary penalties related to these violations, Huang said.

In the first 11 months last year, 305 people were punished for their wrongdoing in environmental pollution cases, she said.