The U.S. government caught a big fish when they hauled in the “ruthless” seafood mogul called The Codfather.

Federal prosecutors say a Massachusetts fishing magnate known as Carlos “The Codfather” Rafael has agreed to plead guilty in a scam involving catch quotas and smuggling money to Portugal.

Rafael, 64, owns the largest fleet of fishing boats in New England through his Carlos Seafood business based in New Bedford, Mass.

The feds claim the sultan of seafood was falsely claiming his vessels were catching haddock or pollock, when they were really catching rarer, pricier species subject to stricter quotas.

During the four-year period the indictment covered, officials say The Codfather scammed them on more than 815,812 lbs of fish. The profits? $660,000 in cold, hard cash

His downfall came in an undercover sting when agents posed as organized crime figures wanting to buy fish — and then lured The Codfather in, the New Bedford Standard-Times reported.

According to Hakai magazine, the malevolent fishmonger was selling his illegal catch to mob associate Michael Perretti. Perretti — a convicted felon — ran South Street Seafoods in the heavily mob-infiltrated fish market in New York.

A story in Hakai magazine said Rafael began building his empire after he was released from prison in the early 1980s following an IRS beef.

The magazine said Rafael ruled the docks of New Bedford like some kind of seafood-soaked potentate.

But environmentalists — and competitors — fear that Rafael’s antics have created misleading data on the true state of the fish stocks.