Prosecutors in Panama say they have formally arrested the partners of a law firm at the centre of last year's Panama Papers scandal, in which thousands of documents related to off-shore accounts were leaked.
The arrests are related to corruption and bribery allegations involving a Brazilian construction firm, Odebrecht.
Ramon Fonseca and Jurgen Mossack, who were partners at Mossack Fonseca, face charges of money-laundering.
The Panama Papers leaks involved millions of documents stolen from the law firm and leaked to the media in April 2016.
The papers are reported to have come from corporate businesses in countries including New Zealand.
They showed how some wealthy people were using offshore firms to evade tax and avoid sanctions.
Announcing the arrests, Panama's Attorney General, Kenia Porcell, said information "allegedly identifies the Panamanian firm as a criminal organisation that is dedicated to hiding assets or money from suspicious origins".
The pair will be held in detention because they are considered a flight risk.
A defence lawyer for the two men described the evidence against them as "weak".
Odebrecht has admitted to paying $1 billion in bribes to obtain contracts in 12 different countries.
Mossack Fonseca denied wrongdoing in the case and said it was the victim of a computer hack. It maintained the information leaked was misrepresented.
Mr Fonseca served as a minister in Panamanian President Juan Carlos Varela's government, but stepped aside earlier in 2016 after separate allegations linked his law firm to the corruption scandal engulfing Brazil's state oil company.