A Philippines senator and staunch critic of President Rodrigo Duterte 's war on drugs has been arrested by law enforcement agents after charges were filed in court alleging that she received money from drug dealers inside the country's prisons.

Senator Leila de Lima is accused of orchestrating a drug-trafficking ring when she was justice secretary during the 2010-2015 administration of Benigno Aquino.

"The truth will come out and I will achieve justice. I am innocent," she told reporters shortly before law enforcers escorted her away from her office on Friday.

De Lima, her former driver and bodyguard, and a former national prison official were ordered to be arrested by a local court on Thursday after a judge found merit in criminal charges filed by the Department of Justice last week.

De Lima has denied the charges, calling herself a victim of political persecution and saying that she has long prepared herself to be the first "political prisoner" under the Duterte administration.

"While the issuance of the warrant of arrest is questionable, I do not have any plans to evade it," she said, calling the order premature as the court has yet to hear the response from her lawyers.

READ MORE: Duterte accused of paying police to kill

She slept in her Senate office overnight and then gave herself up to armed officers in flak jackets, who put her in a van and drove into morning rush-hour traffic apparently towards police headquarters.

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

Since his inauguration on June 30, an anti-drug drive has seen more than 7,000 people killed over suspected drug links - with about 60 percent of the deaths carried out by unknown assassins.

De Lima has previously called for foreign intervention to put an end to the "state-inspired" extrajudicial murders, which she said have been instigated by Duterte since his election to power.

De Lima also led a series of Senate investigations over allegations that police officers were involved in the killings, and that hired killers were operating under orders from police.

Aries Arugay, associate professor of political science at the University of the Philippines-Diliman, told Al Jazeera that the senator will use her detention to highlight the president's controversial policies.

"Senator de Lima has been taunting the Duterte administration to arrest her for months. She boldly says she is its fiercest critic … What is happening right now is she is really using this as her platform for her own politics ," Aurgay said.

Trumped up charges

De Lima's supporters insist that she is innocent and that the charges are trumped up to silence one of Duterte's most prominent critics.

In a statement to Al Jazeera, Senator Paolo Aquino condemned the "political persecution" of his fellow opposition Senate member.

"This arrest is purely political vendetta and has no place in a justice system that upholds the rule of law. This is condemnable.

"We reiterate that an arrest based on trumped-up charges is illegal," he said citing the "haste" in de Lima's arrest.

De Lima previously claimed that she was targeted because of her criticism of Duterte's drug war policy.

During her time as head of the country's human rights body, de Lima led the investigation into the alleged extrajudicial killings of an estimated 1,000 drug suspects in Davao, while Duterte was mayor of the city.

When Duterte won as president in 2016, his feud with de Lima continued.

At one point he called on her to "hang herself", after he ordered prosecutors to investigate the senator's alleged links to the drug syndicate.

This week, de Lima branded the president a "sociopathic serial killer" after new allegations surfaced accusing Duterte of ordering drug killings in Davao.