The Justice Department charged three employees of a Navy contractor, including the company’s president and CEO, with dumping contaminated water from U.S. Navy ships into the ocean near Japan.

A federal grand jury indicted three Japanese nationals on Tuesday who work for Kanto Kosan for a scheme that prosecutors say was carried out over more than a decade, the department announced on Wednesday.  

The defendants include Kanto Kosan’s CEO and president, Sojiro Imahashi, as well as company managers Tsuyoshi Ifuku and Yuki Yamamiya, who were charged with 11 counts of conspiracy, fraud and false claims.

The U.S. Navy had contracts with the Yokohama, Japan-based company between 2007 and last year that amounted to about $120 million, with tens of millions for treating and discarding oily wastewater from the Navy ships in Japan in compliance with environmental regulations.

But prosecutors allege that in about 2007 the defendants at Kanto Kosan ordered the minimal treatment of oily wastewater, so that contaminants were not visible, before dumping it in the ocean. The contractor was supposed to purify the water through filters before disposing it into the ocean.

To get around regulatory tests, the defendants are accused of having a storage tank on the treatment barge to be full of tap water and of having testers take samples from tanks of tap water.

“As a result, the U.S. Navy was deceived into believing Kanto Kosan was properly treating the OWW, and into paying its invoices,” a Justice Department release said.

A Navy spokesperson told The Hill in a statement that it is "aware that three Japanese nationals working with Kanto Kosan, a company that has wastewater disposal contracts with the U.S. Navy, have been indicted by the U.S. Department of Justice for allegations of wrongdoing related to its wastewater disposal."

"Due to the nature of the charge," the spokesperson referred additional questions to the Justice Department.

The indictment comes after The Wall Street Journal reported in 2019 about the alleged dumping scheme, citing three former employees, which Kanto Kosan denied at the time. 

“We’re puzzled and currently consulting with our lawyer about what action to take,” Yamamiya told the Journal on Thursday. “For now, we can’t make any further comment.”

The Hill has reached out to a contact for the company for comment.

-Updated 5 p.m.