(CNN) —  

Philippines news website Rappler and its chief executive have been indicted on tax evasion charges, the latest in a case that free speech and civil liberties advocates have warned is part of a wider crackdown on dissent by President Rodrigo Duterte’s administration.

Rappler said five cases were formally filed against Ressa and Rappler Holdings in two courts, just weeks after the Philippines Department of Justice announced it had found probable cause to indict the pair.

Philippines officials say some of the charges stem from Rappler and Ressa failing to declare about $3 million in 2015 on tax returns from an investment by the Omidyar Network, a fund created by eBay founder and philanthropist Pierre Omidyar.

Earlier this week, the Committee to Protect Journalists urged Philippine authorities to drop the charges against Rappler, calling the ordeal a “politicized persecution” and “a clear and present threat to press freedom.”

Ressa, an award-winning journalist who previously served as a CNN bureau chief, and Rappler’s lawyers maintain the charges have to do with the website’s critical coverage of Duterte.

“I’ve long run out of synonyms for the word ‘ridiculous.’ The basis of this case is that Rappler is classified as a dealer in securities. I am definitely not a stockbroker,” Ressa told CNN Thursday, after news of the charges broke.

Francis Lim, Rappler’s legal counsel, said that Rappler had not evaded taxes with respect to the 2015 investment.

“This is a clear form of continuing intimidation and harassment against us, and an attempt to silence journalists,” Rappler said in a statement after the government announced its probable cause findings in early November.

Rappler has been a consistent thorn in the side of the Duterte administration, closely documenting its so-called “war on drugs,” a widespread crackdown that has been condemned for encouraging police and vigilantes to commit extrajudicial killings.

“In many ways the government’s attacks against Rappler have made it very clear to us exactly who we are, what our identity is, and for our young reporters who are on the ground, how clear and necessary our mission is today,” Ressa said.

Ressa has also been a vocal proponent of combating the spread of misinformation online. She’s been a frequent critic of Facebook and how the social media network has affected political discourse in the Philippines.

This is not the first time Rappler has been in the crosshairs of Philippine authorities. In January, the Philippines Securities and Exchange Commission (SEC) temporarily revoked Rappler’s registration on the basis that it had violated the country’s constitution over foreign ownership rules.

“The end goal of all of these cases is political harassment,” Ressa told CNN earlier this month. “They want to intimidate us and to stop the stories we’re doing.”

CNN’s Hilary Whiteman and James Griffiths contributed to this report.