Short answer. Yes. Article 235 of the Revised Penal Code punishes a public officer or employee who maltreats a prisoner or detention prisoner under his charge, and it says so in addition to his liability for the physical injuries or damage caused. The lawful detention itself does not excuse the mistreatment.
What the law says
in addition to his liability for the physical injuries or damage caused, shall be imposed upon any public officer or employee who shall overdo himself in the correction or handling of a prisoner or detention prisoner under his charge
Revised Penal Code, Article 235 — Maltreatment Of Prisoners. Read the full provision →
What the law says
by the imposition of punishments not authorized by the regulations, or by inflicting such punishments in a cruel and humiliating manner
Revised Penal Code, Article 235 — Maltreatment Of Prisoners. Read the full provision →
Why it stacks instead of merging
The article is written so that the maltreatment charge sits on top of whatever injury was inflicted, not inside it. The penalty is imposed in addition to his liability for the physical injuries or damage caused. So an officer who beats a detainee can answer both for the beating as an offence against the person and for this offence against the public service. It also does not matter that the detention was perfectly lawful and the warrant valid. Custody is a duty of care, and this article punishes the abuse of that custody. Equally, an unlawful arrest and the mistreatment that follows it are separate wrongs with separate consequences.
What conduct the article describes
Two forms are named. The first is imposing punishments not authorized by the regulations — a penalty the officer simply had no power to hand out, however mild it may look. The second is inflicting punishment in a cruel and humiliating manner, which reaches conduct designed to degrade rather than to injure: forced stripping, being paraded, being made to perform humiliating acts. Both are described as the officer overdoing himself in the correction or handling of the person in his charge. The prisoner does not have to end up in hospital. Humiliation without a bruise can be enough.
The heavier form: beating out a confession
The second paragraph raises the penalty where the purpose of the maltreatment is to extort a confession or to obtain information. There the punishment becomes prisión mayor in its minimum period, temporary special disqualification, and a fine that may not exceed one hundred thousand pesos — the amount set by Republic Act No. 10951 (2017), which revised the fines throughout the Revised Penal Code, so older copies quoting a smaller figure are out of date. Disqualification matters as much as the prison term, because it strips the officer of the position that made the abuse possible. Note too that torture is separately punished under a special law, which carries its own and far heavier consequences.
If this is happening to someone you know
The people this article protects are usually in no position to complain themselves, so relatives and counsel carry the burden. Practical steps matter more than legal theory in the first days: ask for a medical examination and keep the record, note the dates, the facility and the names or descriptions of the officers involved, and photograph visible injuries. Complaints may be pursued criminally and, separately, through the administrative machinery that governs the officer's service. No case of this kind is ever certain. But evidence taken while the marks are fresh is what distinguishes a case that proceeds from one that ends as one person's word against another's.