MANILA (PHILIPPINE DAILY INQUIRER/ASIA NEWS NETWORK) - Despite concerns for their safety, three witnesses - two of them minors - will testify in the Senate on Thursday (Aug 24) to detail how police officers killed Kian Loyd delos Santos, 17, in Caloocan City last week, their lawyer said.

Among the things the witnesses - all female and friends of the slain teenager - will discuss was "how random" a police asset had pointed to Kian, which eventually led to his death in the hands of police officers.

Lawyer June Ambrosio of the Integrated Bar of the Philippines said the witnesses were seeking justice for Kian.

"They are Kian's friends and they feel so bad that he's being maligned in the media and social media as a drug courier, a runner. He's not. He's a good kid. A diligent student. He wanted to be a policeman," Ms Ambrosio said.

She said the witnesses had expressed concern about the possible "disruption of their lives and the safety of their families".

The witnesses - aged 13, 16 and 31 - are under the care of Senator Risa Hontiveros.

Ms Ambrosio said she had met the witnesses several times. She also assisted them on Wednesday when they met representatives from the Office of the Ombudsman and the National Bureau of Investigation at the Philippine General Hospital.

The lawyer said she was considering filing murder charges against the Caloocan policemen involved in the killing of Kian.

Senator Hontiveros' camp would continue to provide sanctuary for the witnesses after they declined to be placed under the custody of the Public Attorney's Office.

The senator also scoffed at criticisms that her decision to help Kian was politically motivated. She said she had been very vocal against systematic killings under the Duterte administration.

Justice Secretary Vitaliano Aguirre II on Wednesday raised doubts about the credibility of the three witnesses, "considering the bias of their handler".

Mr Aguirre stressed that witnesses were welcome to the government's witness protection programme.