Italy's d'Amico Shipping Italia has been fined $4m after admitting oily waste dumping in the US.
US authorities said the company pleaded guilty on Wednesday in Newark to violating the Act to Prevent Pollution from Ships.
The charge involved the 40,000-dwt Cielo di Milano (built 2003) that called in New Jersey, Maryland and Florida a number of time in 2014 and 2015.
The company admitted that seafarers intentionally flushed bilges and oily waste from the engine room into the sea, court documents cited by the San Francisco Chronicle showed.
It also admitted falsifying and destroying records and lying to the US Coast Guard during inspections.
A chief engineer falsified the ship's oil record book to state that bilge water had been processed through control equipment.
Court documents showed a record book was destroyed after the Coast Guard had boarded.
d'Amico lawyer Gregory Linsin said the matter remained under the supervision of the court.
He added: "The company will address the issue following the conclusion of the court proceeding."
The shipowner will serve a four-year probation in the US.
d'Amico has been contacted for further comment.
It has since sold the ship.
Two senior officers pleaded guilty to the offences in 2016.
