Justice Secretary Vitaliano Aguirre wants to know how a supposedly confidential memorandum addressed to the Bureau of Corrections (BuCor) was leaked.
The memorandum was reportedly returning special privileges to some high-profile NBP inmates who are detained in AFP's Custodial Detention Center in Camp Aguinaldo.
These privileges reportedly include the use of cellular phones and air conditioning units as well as access to the internet.
BuCor Legal Office Chief Alvin Lim is said to have signed the document dated December 9, 2016.
Aguirre directed BuCor Director Benjamin delos Santos to investigate the leakage.
He also denied having ordered the the reinstatement of privileges to the inmates.
He described the accusation as mere “hearsay.”
Using the memorandum, Senator Leila de Lima had earlier asked the House of Representatives to investigate Aguirre.
The memorandum was reportedly issued after the inmates linked De Lima to illegal drug trade in New Bilibid Prison (NBP).
The inmates testified against De Lima during the House inquiry in October last year.