MARBLEHEAD — A Marblehead tuna broker has been cleared of federal charges that he orchestrated a scheme to illegally catch and export bluefin tuna. 

Robert Kliss and his Lynn-based business North Atlantic Traders were found not guilty of charges that included conspiracy, smuggling and falsifying records, by a U.S. District Court jury on Friday. 

Kliss, his business and a captain-for-hire, John Cafiero, were indicted in April following a four-year investigation by the National Oceanic and Atmospheric Administration (NOAA) and federal prosecutors. 

The allegations came to the attention of investigators in 2012, after a member of the crew on the famous fishing boat the F/V Hannah Boden came back from a swordfishing trip off the coast of Long Island, New York, and reported to the boat's manager that Cafiero had also been fishing for bluefin. 

That would have been illegal, since catch limits for bluefin tuna had already been reached months earlier. Investigators were also told that Cafiero had caught more than the three-tuna-a day limit that would have been in effect if the catch limits hadn't already been reached. The fish were then moved to other boats to elude detection.  

Investigators were told by other fishermen in New York that the bluefin tuna were being moved onto a truck bearing the name of North Atlantic Traders. 

Investigators alleged that Kliss then arranged to export the tuna to Japan, netting $135,000 from the sales. 

One of the New York fishermen who was a government witness, Michael Papajohn, pleaded guilty in New York to a misdemeanor charge involving violating fishing regulations in 2015. During that proceeding, Papajohn stipulated that he and Kliss had never discussed the status of any fishing permits — something Kliss's attorneys discovered on the eve of trial. 

Prosecutors were preparing to elicit testimony at trial to the effect that Papajohn and Kliss had specifically discussed the lack of a New York permit and that Kliss purportedly had said they would rely on his Massachusetts permit. Judge William Young barred prosecutors from eliciting that testimony. 

During the trial, lawyers for Kliss and his firm also elicited testimony from witnesses who said they were pressured into implicating Kliss and his firm, said Kliss's attorney, Barry Pollack, in announcing the verdict. 

Charges against two witnesses were reduced to misdemeanors. Two other witnesses became part of a confidential informant program. 

"The jury could see how federal agents pressured witnesses to make exaggerated statements and engaged in other misconduct," said Pollack in a press release. 

Pollack also had evidence that Kliss was in British Columbia at the time he was allegedly conducting part of the scheme. 

Cafiero, the captain, pleaded guilty to two counts in the case prior to trial and is scheduled to be sentenced in November. 

Courts reporter Julie Manganis can be reached at 978-338-2521, by email at jmanganis@salemnews.com or on Twitter at @SNJulieManganis.