Ghana’s navy impounded a 70-meter (230-foot) supply vessel traveling from Nigeria to Trinidad and Tobago for illegally dumping oil-based mud, the Daily Graphic reported.

The U.S.-flagged Spirit River, owned by Trico Marine Services Inc., is being held in the western port city of Takoradi after allegedly dumping the mud near the town of Essipon, the Accra-based newspaper said, citing Ghana’s Environmental Protection Agency. The waste originated in the Benniboye oilfields in Nigeria’s Benin State, the Graphic said.

No-one was immediately available to comment when Bloomberg News called the company’s office in Aberdeen, U.K. Calls after hours to Trico’s office in the Woodlands, Texas, weren’t answered.