G.R. No. 217682 - Estrada vs. Sandiganbayan, 5th Division

On September 11, 2013, six whistleblowers executed a joint sworn statement revealing the Priority Development Assistance Fund (PDAF) Scam involving Janet Lim Napoles and several legislators.
The NBI investigated and, on September 16, 2013, filed verified complaints with the Office of the Ombudsman for plunder, malversation, bribery, and graft against those involved, including Senator Jose “Jinggoy” P. Ejercito Estrada (Estrada).

On October 11, 2013, the Ombudsman requested the Anti-Money Laundering Council (AMLC) to probe the bank accounts of Estrada and others. The AMLC sought—and on May 28, 2014, the Court of Appeals (CA) granted—an ex parte order under Section 11 of R.A. 9160 (as amended) to inquire into Estrada’s accounts.
The AMLC discovered transfers to co-petitioner Ma. Presentacion Vitug Ejercito (Ejercito) without apparent justification, leading to a supplemental ex parte application. The CA granted it on August 15, 2014. The Inquiry Report on bank transactions was furnished to the Ombudsman on December 19, 2014.

On June 5, 2014, the Ombudsman filed an information for plunder against Estrada (Php183,793,750.00 in ill-gotten wealth). During bail hearings, the prosecution offered the Inquiry Report and AMLC investigator Atty. Orlando C. Negradas, Jr.’s testimony. On January 23, 2015, Estrada moved to suppress these. The Sandiganbayan denied the motion on February 2, 2015, and denied reconsideration on March 2, 2015.
The petitioners then filed a petition for certiorari, prohibition, and mandamus before the Supreme Court, challenging:

The constitutionality of Section 11 of R.A. 9160 (as amended by R.A. 10167) under due process, privacy, and ex post facto clauses;
The admissibility of the Inquiry Report as “fruit of the poisonous tree”;
The failure to apply strict scrutiny to Ejercito’s privacy rights.

The Office of the Special Prosecutor and the AMLC opposed, defending the AMLC’s ex parte powers and the validity of the amendment.

Does Section 11 of R.A. 9160, as amended by R.A. 10167, violate the constitutional rights to due process and privacy?
Is R.A. 10167, insofar as it allows ex parte bank inquiries without prior notice, an impermissible ex post facto law when applied to transactions predating its effectivity?