Metro Manila (CNN Philippines) — The Philippine National Police (PNP) on Friday promised to present to the Senate all active police officers tagged by Senate witness Edgar Matobato as members of the so-called Davao Death Squad.

Matobato, a self-confessed DDS hit man — and claims to have received kill orders from then Davao City Mayor Rodrigo Duterte — named 23 personalities as members of the DDS, including 19 cops.

Also read: Ambush survivor files frustrated murder charge against Matobato

"We're looking at who are still in active service and ask them to appear before the Senate inquiry next week," PNP Spokesperson Senior Supt. Dionardo Carlos told CNN Philippines in a phone interview.

"I saw the list. Personally I have not been assigned in Davao but Davao PNP has confirmed some of the names mentioned," Carlos added.

He did not elaborate, saying he still has to wait for the official release of names from the directorate. "But before the scheduled hearing, we will have them," he said.

Carlos clarified the police officers will be summoned not because Matobato's claims are true, but only because the PNP is following the Senate's order.

In case the policemen will appear on the next hearing set on September 28, Senator Panfilo Lacson on Thursday suggested they be allowed to testify in an executive session — something that Senate Justice and Human Rights committee chairman Richard Gordon and Senator Leila De Lima agreed on.

Matobato earlier told Senate the DDS killed over 1,000 people upon orders of either Duterte or his son, Paolo Duterte. He said his cohorts were cops from the Davao police's heinous crime unit.

Also read: Paolo Duterte slams Matobato's claims

Also read: Duterte says Matobato lied in his testimony

Here is the list of police officials alleged by Matobato as part of the DDS:

SPO4 Arthur Lascanas

Police Chief Inspector Jacy "Jay" Francia

Police Chief Inspector Fulgencio Pavo

Police Chief Inspector Ronald Lao

SPO3 Jim Tan

SPO4 Sanson "Sonny" Buenaventura

SPO1 Reynante B. Medina

SPO1 Bienvenido Furog

SPO1 Vivencio "Jun" Jumawan

SPO2 Enrique "Jun" Delos Reyes Ayao

SPO3 Jun Laresma

SPO2 Rizalino "Bobong" Aquino

SPO3 Donito "Pogi" Ubales

SPO1 Jun Bisnar

SPO1 Gaston Aquino

Police Senior Superindent Isidero "Dick" Florivel/Florobel

Police Senior Superintendent Rey Capote

Police Senior Superintendent Tony Rivera

Police Senior Superintendent Dionisio Abude

PNP officials said they are conducting their own probe on Matobato's allegations, although Carlos earlier said the PNP is not yet investigating the cops' alleged involvement in the DDS because of lack of basis, noting inconsistencies in Matobato's claims and the absence of a judicial affidavit.

"If it's true, we will file a case against those persons involved," said Shella Castillo, Legal Affairs Division chief of the PNP-Internal Affairs Service.

The PNP assured the public it will be fair in its investigation despite earlier pronouncements by PNP Chief Ronald Dela Rosa that the Davao Death Squad does not exist.

Related: Duterte: There is no Davao Death Squad

CNN Philippines' Correspondent Gerg Cahiles and Digital Producer Eimor Santos contributed to this report.