CHANGSHA, Dec. 29 -- The procuratorate in central China's Hunan Province Sunday said it has launched an investigation into a major electoral fraud.

Also on Sunday, the CPC's discipline inspection commission in Hunan said the fraud scandal has led to investigation of 431 Communist Party of China (CPC) members and government workers.

Those suspected of having broken the law will be passed on to judicial authorities, the commission said.

On Saturday, the provincial legislature announced that more than 500 local lawmakers have been disqualified, dismissed or resigned for the electoral fraud.

Altogether 527 municipal lawmakers were present at the election of provincial lawmakers during the first session of the 14th Hengyang municipal people's congress between Dec. 28, 2012 and Jan. 3, 2013.

Investigation has shown that the 56 lawmakers elected offered 110 million yuan (18 million U.S. dollars) in bribes to 518 municipal lawmakers and another 68 staff.

The provincial legislature disqualified the 56 during a plenary meeting which concluded on Saturday and legislative bodies in Hengyang accepted the resignations of 512 who took the bribes.

Another five provincial lawmakers who were not found to have offered bribes were nonetheless dismissed for "serious dereliction of duty", the statement said. Three municipal lawmakers who did not accept bribes resigned, also for "serious dereliction of duty".

Another six who took bribes had already been transferred outside the city and were no longer in their posts.

Tong Mingqian, then Party chief of Hengyang in charge of the election, was sacked from his new post as vice chairman of the Hunan Provincial Committee of the Chinese People's Political Consultative Conference on Dec. 21.

The fraud, involving such a huge number of lawmakers and a large amount of money, is extremely serious and has had a vile impact, the statement of the provincial legislature said.

"This is a challenge to China's system of people's congresses, socialist democracy, law and Party discipline," it said.