The Bureau of Jail Management and Penology (BJMP) conducted a surprise inspection of Antipolo City Jail in Rizal.
The operation was under the so-called 'Oplan Greyhound' program.
The search did not result in the seizure of any prohibited items.
Authorities found only garbage inside the detention center.
The raiding team said it looked like the detainees were tipped off that the jail was about to be raided.
The last surprise inspection in October this year resulted in the confiscation of several contrabands.
The jail was designed to accommodate only 86 inmates.
1,346 detainees are currently languishing in this facility as they await the court's decisions on their criminal cases.
