Coast Guard opens criminal probe into cruise ship MSC Poesia over a possible 'magic pipe' oil-dumping scheme

The U.S. Coast Guard has opened a criminal investigation into the cruise ship MSC Poesia over allegations that it illegally dumped oil at sea, CBS News reports, citing a U.S. official familiar with the probe.

The case involves a so-called "magic pipe," in which a ship routes oily waste into its gray water system, the water from sinks and showers that ships may legally discharge far enough from shore. Sending oil out that way is illegal under federal law.

The ship was detained at the Port of Miami earlier this month after the Coast Guard, which can inspect foreign-flagged vessels entering U.S. ports, "identified deficiencies with systems on board the vessel." More than 2,000 people were on board at the time, a source told CBS News. MSC Cruises called it a "regulatory matter." The ship was cleared to leave Miami on Thursday.

The investigation could reach crew members, the ship's owner and anyone directly involved, the official said. CBS News said it had asked MSC Cruises for comment.

Magic-pipe cases can bring heavy penalties. In 2016, Carnival's Princess Cruises paid a $40 million fine and pleaded guilty to seven felonies for dumping oily waste into the ocean, the largest penalty of its kind at the time.