UPDATE 1-U.S. charges four in 'Panama Papers' tax evasion scheme

The fourth defendant, Ramses Owens, was a lawyer at Mossack Fonseca and remains at large, prosecutors said.

U.S. prosecutors announced Tuesday that they have charged four people with ties to the law firm at the center of the massive leak of offshore financial data known as the "Panama Papers" with taking part in a decades-long scheme to evade U.S. taxes.

Three of the four people have already been arrested, the U.S. Department of Justice said. Harald Joachim von der Goltz, a client of the Panamanian law firm Mossack Fonseca & Co, was arrested in London on Monday; Dirk Brauer, an employee of an asset management company closely tied to the firm, was arrested in Paris on Nov. 15; and Richard Gaffey, a U.S.-based accountant, was arrested in Massachusetts on Tuesday, according to prosecutors.

The fourth defendant, Ramses Owens, was a lawyer at Mossack Fonseca and remains at large, prosecutors said. The law firm shut down earlier this year.

Bill Lovett, a lawyer for Gaffey, could not immediately be reached for comment. Lawyers for the other three defendants could not immediately be identified.

The most serious charges in the case, which include wire fraud and money laundering conspiracy, carry a maximum sentence of 20 years in prison. 

(With inputs from agencies.)