An unprecedented leak of millions of documents of secret offshore holdings of 12 serving and former world leaders and 128 other politicians and public office holders has exposed a massive network of crime and corruption that threatens to taint many influential personalities around the globe.

The leak of a cache of 11.5 million records shows how associates of Russian President Putin moved cash totaling some $2 billion through banks and shell companies to foreign jurisdictions.

The leaked documents, which formed the basis for a yearlong investigation by the International Consortium of Investigative Journalists, ICIJ, German newspaper Süddeutsche Zeitung, and more than 100 other newsrooms, also revealed offshore accounts linked to Chinese leader, Xi Jinping, Ukrainian President Petro Poroshenko and the later father of British Prime Minister, David Cameron, or their associates.

The leaked files revealed offshore companies controlled by other prominent international figures, including Barcelona striker, Lionel Messi and his father, the prime ministers of Iceland and Pakistan, the children of the President of Azerbaijan, as well as the king of Saudi Arabia.

The data from the documents, which covers 40 years from 1977 to 2015, showed how big banks and law firms created paper companies in safe heavens and helped influential people secretly move money through the global financial system.

The documents showed that banks helped to create 15,600 such hard-to-detect paper companies and aided them to dodge taxes, conceal suspicious transactions and doctor or falsify financial records.

The leaked documents come principally from records of a Panama-based law firm, Mossack Fonseca, which has branches in Hong Kong, Miami, Zurich and more than 35 locations around the world.

Mossack Fonseca is regarded as one of the world’s top creators of shell companies, which are commonly used to hide ownership of money and assets. Its leaked files contain information on 214,488 offshore entities connected to people in more than 200 countries and territories.

The files include emails, financial spreadsheets, passports and corporate records revealing the secret owners of bank accounts and companies in panama and other safe havens.

After creating the paper companies, the law firm, like others in this kind of business, does everything it can to protect its clients’ secrets. According to the leaked documents, in Nevada, the law firm tried to shield itself and its clients from the fallout from a legal action in U.S. District Court by removing paper records from its Las Vegas branch and wiping electronic records from phones and computers.

Among other underhand deals, the law firm agreed to backdate documents to help its clients gain advantage in their financial affairs.

The Mossack Fonseca leaked files reveal information that is believed might explain some of the secret wealth of Putin as they link a longtime associate of his to several shell companies.

Putin’s friend, cellist and conductor, Sergey Roldugin, is named in the leaked documents as the behind-the-scene hand behind a network operated by associates of the Russian President which has seen more than $2 billion moved through banks and offshore companies.

The law firm’s files list Roldugin as the owner of several offshore companies which received payments from other favoured companies linked to Putin’s associates.

The suspicion is that the cellist is not the direct beneficiary of the payments and that he might have been fronting for Putin associates or the Russian President himself.

The leaked files also indicate that the world’s best soccer player, Lionel Messi and his father, Jorge, were owners of a Panama company, Mega Star Enterprises Inc. Several other shell companies are linked to Messi and the offshore dealings are currently the target of a tax evasion case in Spain. Father and son are alleged to have defrauded Spanish authorities of over 4 million Euros.

Prosecutors have alleged that Jorge used offshore companies in Belize and Uruguay, among other places, to avoid paying tax on his son’s earnings between 2007 and 2009.

In some cases, Mossack Fonseca not only helped fraudsters to hide money obtained through criminal enterprise, it also tried to protect such clients from the law.

For example, the law firm helped two men connected with the use of an asset management company, Fidentia, to loot about $60 million from an investment fund in South Africa.

The leaked documents indicate that at least two of the men involved in the fraud used Mossack Fonseca to create offshore companies and that the firm was willing to help one of the fraudsters protect his money even after authorities publicly linked him to the scandal.

The leaked records also show that one of the men later jailed in South Africa for his role in the fraud, Graham Maddock, paid the law firm $59,000 in 2005 and 2006 to create two sets of offshore companies, including one called Fidentia North America.

Mossack Fonseca records also show that the firm has helped family members of at least eight current or former members of China’s Politburo Standing Committee to create offshore companies. They include President Xi’s brother-in-law, who set up two British Virgin Islands companies in 2009.

The leaked documents equally revealed that the law firm also had as client, Ian Cameron, father of the former British Prime Minister, David. Ian, a stockbroker and multimillionaire, got the Panama law firm to help him shield his investment fund, Blairmore Holdings, Inc., from U.K. taxes.

The fund’s name came from Blairmore House, his family’s ancestral country estate.

Mossack Fonseca registered the investment fund in Panama even though many of its key investors were British. Ian Cameron controlled the fund from its birth in 1982 until his death in 2010.

Other families that benefitted from Mossack Fonseca’s special services include that of Azerbaijan President, Ilham Aliyev, which used foundations and companies in Panama to hold secret stakes in gold mines and London real estate as well as the children of Pakistani Prime Minister, Nawaz Sharif, who also owned London real estate through companies created by the law firm.

In one case that went awry, Mossack Fonseca got its fingers burnt when the authorities in British Virgin Islands fined it $37,500 for violating anti-money-laundering rules because it incorporated a company for the son of former Egyptian President Hosni Mubarak but failed to identify the connection, even after the father and son were charged with corruption in Egypt.

The ICIJ, in its investigative report, quotes the firm as saying that it “does not foster or promote illegal acts.”

“Your allegations that we provide shareholders with structures supposedly designed to hide the identity of the real owners are completely unsupported and false,” it further quoted the law firm as saying.

The ICIJ report also said that Mossack Fonseca stated that backdating of documents “is a well-founded and accepted practice” that is “common in our industry and its aim is not to cover up or hide unlawful acts.”