Philippine National Police (PNP) Director General Ronald dela Rosa on Friday lashed out at the Commission on Human Rights (CHR) for inspecting a Manila Police District station that was later discovered having a hidden detention cell that held at least a dozen people.

Dela Rosa, who went to MPD Station 1 in Tondo, questioned the timing of the CHR inspection.

"Ano ang motibo niyo sa pag inspect sa panahon ng ASEAN (summit)?" he said.

Dela Rosa dared the CHR to inspect the different jails but after the ongoing ASEAN Summit.

He also defended the station's police officers where the hidden detention cell was found.

"Ang pulis ko walang ginawang kalokohan," he said.

Dela Rosa talked to one inmate, who denied that they were being beaten up and held for ransom.

The inmate claimed that they prefer being held inside the hidden detention cell.

President Rodrigo Duterte earlier vowed to look into the secret jail.

"I will look into this. I will call Bato [PNP Chief Dela Rosa]," Duterte told reporters in Malacanang.

On Thursday, the CHR found 12 men and women detained inside a cramped room hidden behind a bookshelf in the Raxabago police station in Tondo.

The CHR said there was no record of the arrest and inquest proceedings for the detainees, who alleged that cops held them in the facility for a week, without notifying their families or lawyers.

The detainees also accused policemen of torturing them and demanding money for their freedom.

They also claimed that inadequate lighting, ventilation, and toilet facilities forced them "to urinate and [do] bowel movements in plastic bags," according to CHR-Metro Manila director Gilbert Boisner.

Supt. Robert Domingo, commander of the Raxabago station, has denied the allegation, insisting instead that those detained in the hidden cell could not mix with other suspects in the station's main cell because no case has been filed against them yet.

Domingo and 12 other officers of the Raxabago station were temporarily relieved to pave the way for an impartial probe.

The PNP Internal Affairs Service (PNP-IAS) is now conducting an investigation into the issue.

PNP-IAS Inspector General Alfegar Triambulo said having a secret cell is considered a grave misconduct and serious irregularity.

"Secret detention is abhorred by no less than the Constitution," he said in a text message.

At least two senators have also spoken out against the maintenance of a "secret jail" for drug suspects.

Senator Panfilo Lacson, a former chief of the Philippine National Police, noted: "If true, these policemen are no better than the kidnap-for-ransom gangs that I used to chase throughout my law enforcement career."

"Those responsible must therefore be treated no differently from those criminal syndicates that they themselves are mandated to neutralize." - with reports from Jeck Batallones, ABS-CBN News; DZMM