State-owned China Minmetals has failed to rectify a series of pollution offences at its rare earth production unit despite being ordered to do so, the Xinhua news agency reported on Thursday, citing the environment ministry.

The Ministry of Ecology and Environment said Ganxian Hongjin Rare Earth Ltd Co, a subsidiary of China Minmetals, had failed to address pollution issues and continued to violate environmental protection laws, the agency said.

The company's four extraction plants and three workshops had significant issues with hydrogen chloride and organic waste gases, it said, adding that the group was notified of the problems last year.

"The firm adopted a passive attitude and did not adopt any measures to rectify the situation," the agency added.

China Minmetals did not respond to an email requesting comment. China Minmetals Rare Earth Co Ltd is one of China's big six authorised state-owned rare earth producers.

China is responsible for more than 90 percent of global supplies of rare earth, and 17 strategic metals which are used in a range of high-tech applications in renewable energy, consumer electronics and defence equipment.

Beijing began a crackdown on unregulated production a decade ago due to the industry's environmental burden, saying the production of millions of tonnes of waste a year had contaminated water and farmland in Jiangxi and Inner Mongolia.

The country has previously used environmental violations in the rare earth industry to crack down on the entire sector and justify production and export restrictions.

The World Trade Organisation allows countries to restrict exports and production on environmental grounds.

Minmetals is one of two state firms under scrutiny in a new round of nationwide environmental compliance audits. Xinhua said last week that 130 people had been reprimanded as part of the investigations.

- Reuters