South Africa said it was concerned Coal of Africa's Vele mine was carrying out illegal activities and that it may halt development at the colliery if the company has flouted environmental laws.

Minister of Water and Environmental Affairs Buyelwa Sonjica said on Jul 30 the government would investigate whether Coal of Africa had fulfilled environmental laws in order to decide whether to halt development of the mine.

"We are concerned about the illegal activities that the company embarked on when this matter was still under discussion, and really that is the main concern that we have," Sonjica said.

She said there was no indication when the government could make a decision concerning the mine, which is expected to cost 2.1 billion rand ($285.9 million) over three years.

Last month Sonjica also raised concerns that the proposed Vele coal mine might increase pollution and hurt the Mapungupwe Heritage site, which also is located close to the Kruger National Park, the country's premier national wildlife park.