A 53 year-old man from Swansea was arrested on Wednesday in connection with a suspected large-scale illegal waste operation.
The Environment Agency and South Wales police raided two premises in Swansea. A total of 18 officers were involved. The man is currently helping with their inquiries.
Lyn Richards, environmental crime team leader for the agency, said: “At this early stage of the investigation, we are working to establish what was going on in terms of this suspected illegal operation. Early estimates are that thousands of tonnes of waste have been deposited illegally at the two sites over a long period of time."