Guatemalan prosecutors charged journalist Jose Ruben Zamora with crimes including money laundering and blackmail.
Zamora was arrested last week and the offices of El Periodico, a newspaper he founded that has accused key political figures in the country of corruption, were raided.
The publication's staff denounced the actions as retaliation for its previous reporting on President Alejandro Giammattei, as well as Attorney General Consuelo Porras, whom the United States designated earlier this year for "significant corruption."
Prosecutor Cinthya Monterroso on Monday charged Zamora with money laundering, conspiracy, influence peddling and blackmail.
At the time of his arrest, a spokesperson for the Public Prosecutor's Office told AFP Zamora was being investigated "not for his journalist work, but as a businessman."
According to Monday's charges, Zamora had asked a banker to help him deposit 300,000 Quetzals ($37,500) into the Guatemalan banking system in order to hide "the true origin" of the funds.
At the hearing, prosecutors presented as evidence the cash Zamora had allegedly delivered to the banker via a courier.
Monterroso said the banker, Ronald Garcia, had told prosecutors that Zamora had possibly obtained the money from several businessmen whom he had "blackmailed" not to publish negative information about them.
Zamora has said that the case against him was a "set-up" by Giammattei and Porras.
The Guatemalan government has distanced itself from Zamora's arrest, which has sparked a wave of calls to respect freedom of expression, as well as warnings of attacks against independent media.
In June, the Inter-American Commission on Human Rights added Guatemala to its list of countries where it has noted serious human rights violations, a charge Giammattei rejects. Cuba, Venezuela and Nicaragua are also on the list.
The public prosecutor's office, under the leadership of Porras, has been criticized for arresting and prosecuting several anti-mafia judges and prosecutors.
