An air pollution control inspector has been expelled from the Communist Party of China and dismissed from public office for taking bribes and helping conceal violations by companies, the top environmental authority announced on Friday.

When Li Jianzhu, who worked with the environmental department of Xinji, Hebei province, was leading an inspection team in the Henan provincial capital of Zhengzhou on Jan 17, his team found environmental violations of six local companies in Zhengdong new district.

The 40-year-old, however, alerted or deleted four of the violations that had been included into a report to be submitted to the top environmental authority after local official Wang Songbo approached him and gave him 10,000 yuan ($1,570), according to a release from the Ministry of Ecology and Environment.

Wang made the offer at the request of the companies. The 39-year-old has been removed from his post as head of the environmental office of Baisha township and was also given a demerit on his record, the ministry release said.

Yang Yafei, 32, another official with the local environmental authority, has also been given a demerit on his record as he helped Wang get in touch with the inspection team, according to the release.

The ministry's environmental supervision and inspection bureau released a statement on Friday, saying that it has circulated the punishment to environmental authorities across the country to remind all environmental officers of the disciplines.

The bureau also said it will maintain a tough stance on violations of discipline. "Any violators will be punished once found."

Li was one of 5,600 officers taking part in the largest-ever air pollution control operation in North China. The one-year assignment started on April 5, although most of the teams only took part in the inspection for two weeks at a time.

While checking the implementation of air pollution controls by local governments and assessing emission monitoring equipment at businesses, the inspectors also closed small plants that were responsible for high levels of emissions in 28 major cities in the Beijing-Tianjin-Hebei cluster.

In addition to air pollution control inspections, the ministry has said it will launch at least six other inspections, including those covering water source protection and environmental violations in processing imported solid waste.

"More local environmental officers will be mobilized to participate in inspections out of the cities they work in. The ministry will give priority to ensure disciplined and honest inspections," the environmental supervision and inspection bureau said in its statement.