81-year-old German national Harald Joachim von der Goltz, a Mossack Fonseca client;
Richard Gaffey, an accountant from Massachusetts;
and Ramses Owens, a Panamanian attorney who worked for Mossack Fonseca.
Three of the four men are under arrest, but authorities say Owens remains at large.
The indictment in detail: The charges include conspiracy, wire fraud, tax evasion and money laundering. Prosecutors say the Panama-based law firm Mossack Fonsecaconspired to circumvent US laws to maintain the wealth of its clients and conceal tax dollars owed to the IRS. They say the scheme dates to 2000 and involved sham foundations and shell companies in Panama, Hong Kong and the British Virgin Islands.
'Playbook' of tax fraud
US Attorney Geoffrey Berman said the defendants "shuffled millions of dollars through off-shore accounts" and had "a playbook to repatriate un-taxed money into the US banking system."
"Now their international tax scheme is over," Berman said in a statement, "and these defendants face years in prison for their crimes."
Jeffrey Neiman, representing von der Goltz, said the indictment "a desperate attempt to salvage an American case out of the Panama Papers," and that his client would be "vindicated at trial."
What are the Panama Papers? The 2016 revelations, first leaked by German daily Süddeutsche Zeitung, illustrated how some of the world's richest people hide their money. The publication of millions of secret documents led to the resignation of the Icelandic prime minister and cast the spotlight on the financial affairs of leading politicians in Argentina, China and Russia, among others.