Former Chief Presidential Legal Counsel Salvador Panelo said on Wednesday that Vice President Sara Duterte could file a complaint for malicious prosecution against the National Bureau of Investigation (NBI) if the agency fails to produce evidence after completing its investigation into her alleged assassination threat.

Speaking to reporters after the impeachment trial, Panelo said the NBI could face legal consequences if it pursued a case without sufficient basis.

"Of course. Malicious prosecution," Panelo said when asked whether the vice president could sue the NBI if investigators fail to establish their case after three to six months.

Asked to explain, Panelo said: "Malisyosong pag-uusig na wala namang ebidensya. Crime 'yun. That's a crime under the revised state of the law."

NBI Director Melvin Matibag testified this week before the Senate impeachment court that the bureau expects to complete its investigation into Duterte's alleged assassination threat within three to six months.

During cross-examination, Matibag was asked whether the NBI could identify the alleged assassin whom Duterte supposedly contracted within that timeframe. He replied that the likelihood was "6 to 7" on a scale of one to 10.

The NBI opened its investigation following Duterte's 23 November 2024 online press conference, during which she said she had instructed someone to kill President Ferdinand Marcos Jr., First Lady Liza Araneta-Marcos and Speaker Martin Romualdez if an alleged plot against her succeeded.

Duterte has since maintained that her remarks were taken out of context and did not constitute a direct threat. The NBI, meanwhile, has said its investigation seeks to determine whether criminal liability exists.