Discipline watchdogs in Hunan province have launched an investigation into a bribery scandal during the election of the provincial legislative body after a candidate revealed he had given money to more than 300 voters.

Huang Yubiao, 64, chairman of Dayawan Guangbao Industry, a property development and construction material company, published posts on several popular Chinese websites in mid-January saying he had paid about 320,000 yuan ($51,400) to 320 voters last December in an election of the provincial people's congress.

An investigation team of provincial discipline inspectors and legislators has confirmed Huang's allegation and begun to look into it, local officials said.

"At first I prepared more than 470 envelopes with 1,000 yuan in each and later gave 320 of them to voters," he was quoted by Xinhua News Agency as saying on Tuesday. "Then I came to realize that this act was actually meaningless so stopped distributing the remaining 150 envelopes."

The money was given to deputies to the people's congress of Shaoyang, where Huang was born and ran for a post in the provincial people's congress.

In China, deputies to the national, provincial and city-level people's congress are elected by representatives of lower level assemblies. For instance, provincial congress members are elected by deputies to city congress, and city deputies by their county or district counterparts.

A deputy head of the standing committee of Shaoyang People's Congress had encouraged Huang to bribe city deputies, Huang said, adding that Zhao Lisha, head of the standing committee, warned him not to buy votes, otherwise he would incur complaints or reports.

A total of 534 deputies took part in the election on Jan 2, which meant a candidate would win with more than 267 votes in his or her favor. Huang received 241 votes.

Seventy-six candidates out of the 97 nominated by local government and city deputies were elected deputies to the provincial people's congress in the election, according to Mao Wensheng, a liaison official of the city legislative body.

Mao said Huang was nominated by the city government because he is well known for generous donations to charity, noting there were many entrepreneurs from the private sector who were nominated for the election.

A city deputy said Huang lost the election because voters were not familiar with him. However, Huang said the true reason was that his bribes were "not enough", Guangzhou-based Southern Metropolis Daily reported.

Huang told the newspaper that after he lost the election, deputies who took his bribe had returned the money and he had sent text messages to the Party chief and head of the city congress to report the bribery scandal.

He also mailed materials to provincial leaders using his real name, the report said.

"I'm determined to sacrifice myself with real-name reporting. My goal is to call for improvements for the current election system of people's congress," Huang said. "Election organizers must make public the candidates' information and their promises made during the campaign."

The entrepreneur said he does not worry about being charged with offering bribes.

"I've checked with the laws about the crimes of offering and taking bribes and I think my revealing the bribery deserves rewards from authorities or courts rather than punishment, since I have had my money returned and I reported this matter to authorities in my real name."

However, law professors said they did not agree with Huang.

"It is good for Huang to expose the scandal himself but he should still be punished for offering bribes in the first place," Han Yusheng, a professor of criminal law with Renmin University of China in Beijing, told China Daily on Wednesday.

"The fact that he spoke to the media or published posts on the Internet could not be deemed as a voluntary confession to law enforcement departments, and even though he voluntarily confessed to authorities, this could only be a mitigating factor rather than a reason for exoneration."

Han said the behavior of offering bribes must be chastised like taking bribes.

"As far as I know, bribery still plagues grassroots elections and some senior officials of local congresses even assist with or connive in the act of bribing," said Lin Zhe, a law professor at the Party School of the Communist Party of China Central Committee.

She suggested authorities enhance the transparency and openness of congress elections and facilitate the public to improve supervision of candidates and deputies.

Wen Xinzheng in Changsha contributed to this story.