DULUTH, Minn. — The oceangoing freighter Cornelia that has been anchored in Lake Superior offshore from Duluth for nearly two weeks is the subject of an investigation for “alleged violations of U.S. environmental regulations,” the U.S. Coast Guard confirmed Tuesday.

“Due to the ongoing investigation, the … vessel and crew are prohibited from leaving Duluth until cleared by U.S. Customs and Border Protection,” the Coast Guard said in a statement issued by its office in Cleveland. “The vessel and crew do not pose a public safety threat. Speculation that the ship is held in port due to any safety concerns (is) false.”

The Coast Guard said it will not release additional information while the investigation is under way.

It was first reported on Nov. 7 that the ship was being held at anchor as part of a federal probe. At that time the Coast Guard directed questions to the U.S. attorney’s office for the District of Minnesota, which confirmed the investigation but declined to reveal any details about its nature.

A message left this week with the U.S. attorney’s office was not returned.

The Cornelia took on grain at the CHS Inc. elevator in Superior, Wis., on Nov. 3 and 4.

Greg Ukkola, grain operations manager for the Wisconsin Department of Agriculture Grain Regulation in Superior, said earlier this month that a stowage exam of the vessel and its holds was done on Nov. 1, while the ship was anchored in Duluth harbor.

“We did an initial stowage examination on the ship to see that it was fit to load grain into, and we examined the grain as it was being loaded,” Ukkola said. Everything about the exams was routine, he said.

After being loaded, the Cornelia never got underway. The saltie, built in 2001 and about 575 feet in length, has been stopped at anchor since Nov. 5.

The Cornelia is managed by the German company MST, which operates dry-bulk carriers on the Atlantic Ocean; the ship is registered in Liberia.

In a statement earlier this month, MST managing director Matthias Ruttmann said the Cornelia is owned by a German bank.

“We are fully cooperating with the USCG to shine some light on this,” Ruttmann said. He said MST was conducting its own internal investigation to find out what was happening onboard the Cornelia, and that the company did not want to speculate on the situation pending completion of that investigation.

The captain of the vessel refused to comment when reached earlier this month.

Brady Slater contributed to this report.