“The overall impression given by the internal Garda investigative process was that complaints or matters of concern were put through a process of filtration or distillation so that, by the end of the process, any matter of concern had been removed as a form of impurity, and only what was good was found to remain.”
Royal Dutch Shell has been ordered to pay $48m (£29.4m) in civil and criminal fines over its contractor's involvement in bribing Nigerian customs officials.
The US Department of Justice hit the London-listed oil super-major with the penalty, after Panalpina, which was employed by Shell, agreed to plead guilty to taking bribes on behalf of its clients.
Panalpina, a major Swiss freight and logistics company, must pay $82m in fines after admitting to paying bribes to customs officials in at least seven countries including Nigeria, Brazil and Russia between 2002 and 2007.
Four of Panalpina's other clients in addition to Shell were also fined, including Transocean, Tidewater, Pride International and Noble Corp.
"These companies resorted to lucrative arrangements behind the scenes to obtain phony paperwork and special favours, and they landed themselves squarely in investigators' crosshairs," said Robert Khuzami, the director of enforcement at the US Securities and Exchange Commission.
In total, the six companies must pay $236m in criminal and civil penalties.
These companies, including Shell, admitted they "approved of or condoned the payment of bribes on their behalf in Nigeria and falsely recorded the bribe payments made on their behalf as legitimate business expenses in their corporate books, records and accounts".
A spokesman for Shell said: "Shell fully co-operated with the US Department of Justice and the SEC throughout this investigation.
"Shell has enhanced its compliance programme and internal controls. Staff found to have been in violation of policy were either disciplined or dismissed from Shell."
The settlement brings a long-running investigation into Panalpina and its clients to an end.