“The truth will come out at the right time. They will not be able to silence me and stop me from fighting for the truth and justice and against the daily killings and repression by the Duterte regime.”

De Lima on Tuesday branded Duterte a “sociopathic serial killer” as she called for ordinary Filipinos to stand up in opposition to his drug war, which has seen more than 6,500 people killed since he took office eight months ago.

It was the peak of a decade-long campaign by De Lima, a former human rights commissioner and justice secretary, to expose Duterte as the leader of death squads during his time as mayor of southern Davao city and then as president.

Duterte first raised allegations in August that De Lima had been running a drug trafficking ring with criminals inside the nation’s biggest prison when she was the justice secretary in the previous government.

“I will have to destroy her in public,” Duterte said then as he began a campaign to tarnish her reputation, including by making unsubstantiated allegations about her sex life. “De Lima is not only screwing her driver, she is also screwing the nation.”

De Lima was last week charged with three counts of drug trafficking, and an arrest warrant was issued on Thursday afternoon – triggering a night of high drama as she initially avoided police by seeking refuge at the Senate. She slept in her office overnight, then gave herself up to armed police in flak jackets.

De Lima and her supporters insist that Duterte orchestrated the charges to crush her opposition as well as intimidate anyone else who may want to speak out against him or his drug war.

“People are afraid,” Father Robert Reyes, an activist priest who spent the night at the Senate with De Lima and other supporters, said after her arrest. “If the government can arrest a powerful person like her, what more the little man? That is the implied message of her arrest.”

Amnesty International said on Thursday that it would regard De Lima as a prisoner of conscience.

“The arrest of De Lima is a blatant attempt by the Philippine government to silence criticism of President Duterte and divert attention away from serious human rights violations in the ‘war on drugs’,” it said.

But Duterte’s aides said De Lima’s arrest showed even the most powerful people would be brought to justice.

“The war on illegal drugs targets all who are involved and the arrest of an incumbent senator demonstrates the president’s strong resolve to fight pushers, peddlers and their protectors,” presidential spokesman Ernesto Abella said.

Duterte, 71, won the presidential election last year after promising during the campaign to eradicate drugs in society by killing tens of thousands of people.

He launched the crackdown immediately after taking office in June and police have reported killing 2,555 drug suspects since then, with about 4,000 other people murdered in unexplained circumstances.

Amnesty has warned that police actions in the drug war may amount to crimes against humanity.

Duterte has variously denied and acknowledged his role in death squads in Davao. As president he has repeatedly urged police to kill drug addicts as well as traffickers. But Duterte’s aides insist he has never broken any laws.