The anti-corruption museum in Liaoning province is the largest one of its kind in China and is free of charge. [Photo/Xinhua]

Zhou, the former head of law enforcement agencies, was reported to have formed several patronage networks within the fields he had taken charge of. Many officials from local governments and central departments, as well as State-owned enterprises, have been investigated in connection with Zhou's case, Chinese media said.

Zhou has been expelled from the Party and placed under investigation.

Xu, a retired general and former vice-chairman of the Central Military Commission, is also said to have set up factions within the People's Liberation Army. A host of senior officers of the PLA are now under internal probe for allegedly being involved in Xu's case.

As a powerful officials in the PLA, Xu was found to have taken advantage of his position to assist with the promotion of others, accepting bribes, and to have sought profits for others in exchange for bribes, according to military investigators.

PLA prosecutors wrapped up the investigation into Xu and began the filing process in late October. He is the highest-level PLA officer to be investigated and charged in more than 30 years.

Chinese media claimed that Ling, a senior Party official and national political adviser who became the latest one to have fallen, established a secretive network with other high-ranking officials and business magnates who are from his home province of Shanxi to expand his influence.