More than 7,700 people have been killed in the narcotics crackdown since Duterte took office on June 30, about 2,500 in police operations, while the rest are being investigated.
Human rights groups believe many other deaths that police attributed to vigilantes were carried out by assassins likely colluding with police. The government and police vehemently deny extrajudicial killings have taken place.
Sen. Leila de Lima, her former driver, two bodyguards and a former national prison official face arrest next week once a court has issued arrest warrants, Justice Minister Vitaliano Aguirre told a news conference.
“These are non-bailable offenses under the country’s anti-drug laws,” Aguirre said, adding that a guilty verdict would bring a penalty of life imprisonment. “These are not the product of politics, the cases were carefully studied.”
According to information filed at the Muntinlupa trial court in the south of Manila, the capital, de Lima received 5 million pesos ($100,000) delivered to her home when she was justice minister in the years 2010 to 2016.
She also allowed a convicted felon to run a drug trading business from inside national prisons, which police described as controlling about 70 percent of large-scale sale and distribution in the Philippines, it added.
“The criminal charges and prosecution are nothing less than a politically motivated act,” de Lima said, denying all the allegations, and vowing to fight a battle for human rights and democracy.
“This is the kind of vindictive politics that we only expect from this regime,” she said in a statement, accusing Duterte of trying to “clamp down on any vocal opposition to a policy of extrajudicial killing.”
Three weeks ago, Duterte halted all anti-drug operations by police, after a South Korean businessman was kidnapped and strangled to death inside the national police headquarters in October.
Aguirre said the justice ministry would refer another case against de Lima to the anti-graft body and investigate allegations that she received about 8 million pesos ($160,000) from a known drug dealer in 2015 for her senatorial election campaign.
The latest tally given to AFP on Friday showed an extra 146 people had died since the Jan. 31 stand-down was ordered, which rights groups said showed extrajudicial killings were continuing.
“The targets are still the same, as far as we are concerned: people linked to drugs and who live in poor neighborhoods,” Wilnor Papa, campaign official for the Philippine branch of Amnesty International, told AFP.
Papa said unknown assailants were now killing between nine and 10 people daily. This compared with about 30 people a day being killed by police and unknown assailants when officers were still leading the crackdown.
In one new shooting incident covered by an AFP photographer, police found four men dead inside a shanty in northern Manila before dawn on Thursday, in a scene very similar to those covered at the height of the drug war.
Witnesses said unknown suspects broke into the house and started shooting, while three other men were shot dead in separate incidents elsewhere in the same district that night, local police told AFP.
In an earlier report, Amnesty said the police were guilty of systemic human rights abuses in the drug war, including shooting dead defenseless people, paying assassins to murder addicts and stealing from those they killed.
It also said police were being paid by their superiors to kill.
Duterte has since ordered the much smaller Drug Enforcement Agency to lead the drug crackdown, with the support of the military.
Derrick Carreon, spokesman for the 1,791-member drug agency, told AFP there had been far fewer killings by authorities since it took charge, without giving figures.