The company reached a settlement with federal prosecutors in the US after admitting it had violated the terms of its probation stemming from a 2016 conviction for discharging oily waste from Princess Cruises ships.

During this original case three years ago, Carnival Corp paid a $40 million fine and was put on probation for five years.

Carnival Corp, which operates nine cruise brands around the world, has admitted its ships have continued to release “gray water” in areas such as Glacier Bay national park in Alaska, as well as discharging plastic waste in the Bahamas, which can be harmful to marine life.

Carnival chief executive Arnold Donald pleaded guilty to the breaches of its probation during a court hearing in the company’s home city of Miami.

The cruise company will also face more stringent oversight of its activities during the final years of its probation period.

Carnival Corp said in a statement that its deal with the US Department of Justice included “new initiatives, improved procedures, additional training and significant investments to ensure we have the strongest and most sustainable environmental compliance programme possible”.

“Carnival Corporation remains committed to environmental excellence and protecting the environment in which we live, work and travel,” the company added. “Our aspiration is to leave the places we touch even better than when we first arrived.”