The Philippines' top policeman, who leads the nation's deadly drugs crackdown, quit on Monday as he faces allegations of protecting officers accused of selling a huge haul of seized narcotics.
Though the scandal dates from before Oscar Albayalde's time as national police chief, it has raised fresh criticism of President Rodrigo Duterte's signature anti-narcotics campaign, which is key to his massive popularity among Filipinos.
As part of Duterte's internationally condemned initiative, police have killed thousands of alleged dealers and users since mid-2016, but critics say the wealthy and powerful have been largely untouched.
Albayalde's resignation comes days after two former police officials implicated him in a 2013 raid in which officers in a province near Manila allegedly seized and then sold parts of a large methamphetamine haul.
One former official claimed Albayalde intervened to protect the officers from disciplinary action, while the other said he received money from the drug sale.
Criminal charges against the officers allegedly involved in the matter were dismissed in 2017. However, prosecutors have now re-opened the case and summoned the men for questioning.
Albayalde, then the province commander, has vehemently denied any wrongdoing. He said the allegations may have been an effort to gain publicity for people interested in his job.
He was due to retire November 8 after serving as national police chief since April 2018.
"I thank President Rodrigo Roa Duterte for his trust and confidence," Albayalde said in a message announcing his departure.
Though the issue has been bubbling for weeks in Senate hearings, Duterte has remained largely silent on the matter.
He had pledged to root out deep-seated corruption in the Philippine police but has repeatedly expressed frustration and anger with the extent of the problem.
Neri Colmenares, a lawyer for families pushing for an International Criminal Court prosecution of those behind the drug war, branded the allegations against Albayalde a "major embarrassment".
"Even the presiding officers of the PNP (national police) are involved in drugs themselves," he said. It "shows what we've been saying all along, this is targeted against the poor".
Philippine police say they have killed just over 5,500 suspects who fought back against arrest, but rights groups say the true toll is four times higher and may amount to crimes against humanity.
International Criminal Court prosecutors have launched a preliminary probe of the killings, and the UN's top human rights body has approved a review.