A Greek shipping company and its chief engineer were indicted Tuesday for witness tampering and falsifying records to hide the illegal discharge of waste oil into the sea.

The Department of Justice (DOJ) announced the six-count indictment against Chartworld Shipping Corporation, Nederland Shipping Corporation, and Chief Engineer Vasileios Mazarakis. A federal grand jury in Wilmington, Delaware acted after hearing evidence that the company failed to keep accurate pollution control records and falsified records. The charges also include obstruction of justice and witness tampering, according to the DOJ.

The case was brought under the Act to Prevent Pollution from Ships (APPS), a U.S. law that implements the International Convention for the Prevention of Pollution from Ships, commonly known as MARPOL. The law has a whistleblower provision and investigators say they use it routinely when witnesses come forward.

The case involves “overboard discharges of oily mixtures and machinery space bilge water” from a Bahamian-flagged cargo vessel. The discharges were discovered when the M/V Nederland Reefer entered the Port of Delaware Bay in February. The witness tampering charge is linked to destruction of evidence and orders to “lower level crew members to withhold evidence from the Coast Guard. “

The ship’s Oil Record Book “failed to accurately record transfers and discharges of oily wastewater on the vessel.”

The APPS  was the subject of a panel discussion in Washington last week on the role private citizens and whistleblowers play in the detecting off-shore crimes.

Anton DeStefano, Lieutenant Commander of the U.S Coast Guard’s environmental law division, said they can often identify illegal dumping via falsified records.  But whistleblowers who come forward make a stronger case, he said during the panel.

“If you are going to prosecute a case, the judge or jury most of the time wants to hear someone say – this is what happened. or I did it,” he said

He reported that 23 corporations were convicted in 2016 and paid $70 million in penalties under the APPS.

A recent report on of 100 APPS settlement agreements  found they resulted in $177 million in fines. In those cases, $33 million went to whistleblowers and $56 million went to environmental programs like the Florida National Keys Marine Sanctuary.

The APPS whistleblower provision allows for international application – foreign whistleblowers and international companies can be under US jurisdiction. These rewards, at no cost to taxpayers, incentivize whistleblowers to report APPS violations, which aids the US government in detecting and prosecuting crimes related to wildlife and environmental laws and regulations. The whistleblower program effectively addresses issues of corruption at-home and abroad.