Sometime between now and Sept. 4, 2008, Honduran businessman David Henson McNab will be released after nearly eight full years in a U.S. federal prison — all because, prosecutors say, he was too selfish about shellfish.

American importers Robert Blandford and Abner Schoenwetter, who entered prison three years later than McNab (unlike him, they had stayed free pending appeals), still must serve three years of their eight-year sentences.

Their crime? In 1999, they accepted from McNab some 70,787 pounds of spiny lobster tails, unloaded at Bayou La Batre, and less than 5 percent of them, horror of horrors, were too short. Even worse — gasp! — they were packaged not in the required cardboard containers, but in plastic.

Both the packaging and the undersized catch allegedly violated Honduran sea-harvest laws. An American law called the Lacey Act makes it illegal in the United States to import goods in contravention of another nation’s laws.

The Lacey Act makes some sense: It promotes reciprocity among nations. After all, we would certainly want a foreign government to refuse to allow the importation of something like American eagle meat, for instance, in contravention of our own wildlife-protection laws.

But there’s a vast difference between reciprocity and prosecutorial audacity. At the very least, one would expect that U.S. Justice Department officials would not use a foreign law as an excuse to prosecute a personal, domestic agenda.

And we would certainly not expect to continue enforcing such an agenda when the foreign government itself says its own laws were not actually violated.

But amazingly and inexcusably, that’s what happened in the McNab case. Here’s the tale:

The original violation with which the lobstermen were charged involved the too-small lobsters (taken before they were big enough to reproduce and replenish the resource).

Prosecutors made the value of the infraction larger by adding the “improper packaging” charge, thus applying it to the value of the whole cargo rather than just the undersized portion.

Then, because it was contraband, prosecutors turned it into a “smuggling” charge — and then, because the businessmen used the money from the alleged smuggling for other goods and services, prosecutors charged them with “money laundering” as well.

Suddenly, the allegation of minor civil violations was turned into a major criminal case taken over by Long Island drug charge defense lawyers. That’s how the three eight-year sentences were handed down.

Eight years. In federal prison. To enforce a foreign regulation. About undersized lobsters.

Never mind that the importers openly took the lobsters through Customs, seemingly unaware they were doing anything wrong.

Never mind that the U.S. Department of Commerce published an official price list for Honduran lobsters of the very sizes supposedly outlawed.

And never mind that from the very start, there was conflicting expert testimony about whether Honduran law was violated at all. The original trial judge, citing a mid-level Honduran official, allowed the trial to continue, all the way to convictions.

Later, when the attorney general of Honduras wrote to say the regulations at issue had been repealed four years before this case began, the appeals court said it was too late.

“There must be some finality with representations of foreign law by foreign governments,” wrote the 11th U.S. Circuit Court of Appeals. So the men went to prison, even though no existing law had been violated.

McNab and his American co-defendants applied for executive pardons or commutations. No response. Finally, in December 2004, the president of Honduras, Ricardo Maduro, wrote a letter to President George W. Bush.

“In the case of Mr. McNab,” President Maduro wrote, “all the legal bodies of Honduras … have determined that Mr. McNab has not violated any law of Honduras. … I believe the interest of justice will be best served if you assent to the request for clemency.”

No such luck.

Miguel Estrada, the brilliant lawyer whose judicial nomination by Bush was famously filibustered by Democratic senators, represented McNab on appeal. Estrada’s administration connections did not help.

“No one has done squat about it,” he told me this month, in frustration. “I never got the time of day.”

In retrospect, prosecutors did what they always do: Take seriously their charge to enforce the laws.

“Protecting our natural resources is one of the core functions of government,” said Todd Aagaard, a Villanova Law School professor and former Justice Department official who handled the case on appeal for the prosecution.

“Overfishing is a huge problem worldwide,” Aagaard told me recently. “And you have to punish violators enough to make everybody give a second thought before committing a violation. That’s what deterrence is.”

Yes, but even deterrence ought to keep a sense of proportionality. This case lacked such sense entirely, and the courts handled it badly.

It was a case in which the U.S. government claimed to enforce Honduran law, but where the Honduran government said the law no longer exists, and for which there was no U.S. violation unrelated to the original non-offense.

And one defendant was a Honduran who by logic (if not law) should be under the jurisdiction of his own country rather than this one, all about an “offense” that most people would find inoffensive.

“It has always been a mystery to me why the government focused on McNab when he had been coming into this country for years, through Customs, subject to inspections,” said Mobile attorney Donald Briskman, who defended McNab at the original trial. “It has always been my belief that, at the end of the day, the government’s case fell apart through a number of subsequent developments.”

This case has been an abominable injustice from the start. President Bush ought to cut through the idiotic red tape at the Department of Justice and pardon all three men immediately.

By QUIN HILLYER