Three officials were expelled from the Communist Party of China (CPC) over allegations of "serious violation of discipline and law," including bribery and adultery, announced China's top discipline watchdog Wednesday.

According to an announcement posted on the website of the CPC Central Commission for Discipline Inspection (CCDI), Yu Gang, former deputy head of the general office of the Commission for Political and Legal Affairs of the CPC Central Committee, was stripped of his Party membership and official post for having taken advantage of his position to seek interests for others, and for bribery and adultery.

Ji Wenlin, former vice governor of South China's Hainan Province, was also expelled from the Party for taking advantage of his position to seek interests for others, demanding huge bribes and committing adultery.

Tan Hong, a former senior officer in the guard bureau of the Ministry of Public Security, was also expelled.

The CCDI has handed all three cases to prosecutors for suspected infringement of law.

In a previous post on its website, the CCDI made a rare explanation over the definition of "adultery," following heated discussion among the public over the scandal of Dai Chunning, a deputy general manager with China Export and Credit Insurance Corporation, who was dismissed from the Party following graft and adultery accusations.

Adultery, as stated in the post on June 7, refers to voluntary sex between a married person and someone other than his or her lawful spouse. While it is not illegal under China's criminal law, the act of adultery is said to have violated "moral ethics under communism," as well as Party regulations.

Article 150 of "the Chinese Communist Party Disciplinary Regulations" stated that adultery causing a bad impact will receive a warning or serious penalty, while serious violators will be expelled from the Party.

Yu and Ji are among a total of seven officials to be expelled from the Party Wednesday.

The five others, all facing bribery allegations, include Zheng Xinghua, deputy mayor of Yichang in Hubei Province, Xu Tongwen, Qilu University of Technology's former Party secretary and Wang Shiyi, Party  secretary of Xinzhou district in Wuhan, Hubei Province.