President Rodrigo Duterte trusts Solicitor General Jose Calida, being his “alter ego”, on his manifestation to the Court of Appeals that businesswoman Janet Napoles was not guilty of committing serious illegal detention of her former aide.

In a press briefing on Thursday, Presidential Spokesperson Ernesto Abella said he was not aware if Duterte and Calida had a conversation regarding the latter's move on Napoles case.

"I don't know if they had a conversation regarding that. But the president trusts his alter ego's decision," he said.

Abella expressed belief Calida's intervention on the case of Napoles, the alleged mastermind in the multi-billion pork barrel scam, would not affect the government's anti-corruption drive.

"It doesn't change his position regarding corruption," he said, adding that the serious illegal detention case of Napoles was "not connected" to the plunder charges before the Sandiganbayan, the anti-graft court.

Chief Presidential Legal Counsel Salvador Panelo, in a separate interview, expressed belief there was "very strong evidence" on Napoles plunder cases.

Some lawyers have said Calida's move could weaken the plunder cases filed against Napoles, who was convicted by a trial court for illegally detaining her aid and relative, Benhur Luy, the whistleblower in the pork barrel fund scam. Celerina Monte/DMS