Congo ? A government official in Congo suspected of ordering up to 17 tons of radioactive waste dumped in a river in the southeast of the country has been arrested, authorities said Friday.

Environment Minister Didace Pembe declined to identify the person who was arrested because investigations were continuing. He said the waste belonged to a Chinese company called Magma-Lubumbashi, but that the company had not asked that the waste be dumped in the Likasi River.

The mining minister for Congo’s Katanga province announced on a U.N.-backed radio station that 17 tons of “highly radioactive” minerals had been found in the river on Monday. He did not provide further details and could not be reached for comment.

Authorities have issued calls over local radio stations asking people to avoid using the river to drink or bathe, Pembe said.