The leak of more than 11.5 million confidential documents from Panamanian law firm Mossack Fonseca, now known as the Panama Papers, exposed a number of world leaders, celebrities, athletes and criminals for using offshore accounts as tax havens and involvement in legally dubious offshore financial deals.

The findings, published Sunday by the International Consortium of Investigative Journalists after a year-long investigation, show the law firm was assisting its high-profile clients – which include 12 current and former world leaders and 128 politicians and public officials from more than 40 countries – in money laundering and tax evasion.

Russian President Vladimir Putin and his allies are being tied to $2 billion in offshore dealings involving shadow companies and banks, TIME reports.

Other major names include Iceland’s Prime Minister Sigmundur Davíð Gunnlaugsson, Argentina’s Prime Minister Mauricio Macri, Georgia’s former Prime Minister Bidzina Ivanishvili, Ukraine’s former Prime Minister Pavlo Lazarenko and the father of former British Prime Minister David Cameron, Ian Cameron.

“The leaked data covers nearly 40 years, from 1977 through the end of 2015,” ICIJ said in its report. “It allows a never-before-seen view inside the offshore world — providing a day-to-day, decade-by-decade look at how dark money flows through the global financial system, breeding crime and stripping national treasuries of tax revenues.”

While offshore banking is not illegal, the investigation found banks and law firms didn’t follow legal requirements to ensure their clients weren’t involved in criminal activity.

“In some instances, the files show, offshore middlemen have protected themselves and their clients by concealing suspect transactions or manipulating official records,” the report reads.

The leak is one the largest of its kind, exposing more secret documents than Wikileaks in 2010.

Mossack Fonseca said it would not answer specific questions, but stood by its business practices.

“For 40 years Mossack Fonseca has operated beyond reproach in our home country and in other jurisdictions where we have operations. Our firm has never been accused or charged in connection with criminal wrongdoing,” the law firm said in a statement provided to The Guardian. “However, we are legally and practically limited in our ability to regulate the use of companies we incorporate or to which we provide other services.”

Follow Juliegrace Brufke on Twitter

Copyright 2016 The Daily Caller News Foundation