CHANGSHA, Jan. 2 -- Hu Guochu, a senior lawmaker in central China's Hunan Province, has been detained for his suspected involvement in major electoral fraud, a local procuratorate said Thursday.

The provincial procuratorate of Hunan said Hu, the former chairman of the Standing Committee of the Hengyang Municipal People's Congress, had been placed under criminal detention for dereliction of duty.

A statement by the province's discipline inspection commission said Hu received bribes and did not take effective measures to stop vote-buying during an election he oversaw in Hengyang City.

On Saturday, the provincial legislature announced that more than 500 lawmakers in Hengyang have been disqualified, dismissed or have resigned.

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.

An 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.