Ressa, a Time Magazine Person of the Year in 2018 for fighting media intimidation, is facing several government lawsuits that have caused international concern about harassment of journalists in the Philippines, a country long seen as a standard bearer for press freedom in Asia.

Ressa, 56, who is chief executive of the news site Rappler, was convicted of libel last month and sentenced to up to six years in prison, a ruling widely seen as a blow to democratic freedoms under Duterte's increasingly popular authoritarianism. She was freed on bail.

Ressa's latest court appearance is over accusations Rappler falsified tax returns by omitting the proceeds of a sale of depositary receipts to foreign investors, which later became the securities regulator's basis to revoke its licence.

"These charges are politically motivated, it is meant to harass and intimidate, it is meant to be a war of attrition to try to make us afraid to keep reporting," Ressa, a dual US-Filipino citizen, told reporters on Wednesday after she pleaded not guilty to the charges. "The best response to it is to keep reporting."

Rappler has repeatedly challenged the accuracy of Duterte's public statements and his justification for his controversial foreign policy.

It has also reported on alleged atrocities in his war on drugs and probed what it says are massive, state-orchestrated social media hate campaigns against Duterte's critics.

Duterte has publicly lashed out at Rappler, calling it a "fake news outlet" sponsored by American spies.

In the tax evasion case, the securities regulator alleges that Rappler allowed foreigners to illegally own shares in a domestic media firm.

Rappler, a startup, has maintained foreigners never owned shares, but were allowed to invest without voting rights or involvement in operations. Rappler is still operating pending its appeal against its licence being revoked.

Media watchdogs and human rights activists say the charges against Ressa are part of a broader strategy to silence or humiliate opponents of Duterte.

Earlier this month, his allies in Congress voted overwhelmingly in favour of denying top broadcaster ABS-CBN's bid to renew its 25-year licence, an outcome that Duterte had repeatedly promised would happen because of its refusal to air some of his election campaign commercials.

"It is shocking where we are right now," Ressa said.

"It is unthinkable that ABS-CBN shut down. This is the perfect storm where the pandemic and lockdown enabled the government to quickly consolidate power."

Australian Associated Press