Lima, 63, remained jailed, however, as she has one outstanding charge against her.
De Lima has been detained since 2017 on drug charges she says were fabricated by former President Rodrigo Duterte and his officials in an attempt to muzzle her criticism of his deadly crackdown on illegal drugs.
His campaign left thousands of mostly petty suspects dead and sparked an International Criminal Court investigation as a possible crime against humanity.
Duterte, who has insisted on de Lima’s guilt, left office last June at the end of his turbulent six-year term.
Trial court judge Abraham Alcantara said in his ruling that a former senior police official’s recantation led to his decision to acquit de Lima.
“Without his testimony, the crucial link to establish conspiracy is shrouded with reasonable doubt,” he wrote, “which warrants the acquittal.”
Prosecution witness Rafael Ragos, a former head of the Bureau of Corrections, retracted a claim to have delivered money from drug lords to de Lima and said he had been forced by government officials to make it.
De Lima said through her attorney that she was looking forward to her full acquittal on all charges. She has been held in pretrial detention since her arrest without any convictions.
“I have no doubt from the very beginning that I will be acquitted from all the cases the Duterte regime has fabricated against me based on the merits and strength of my innocence. That’s already two cases down and one more to go,” she said in a statement read out by lawyer Boni F. Tacardon.
“I am of course happy that with this second acquittal in the three cases filed against me, my release from more that six years of persecution draws nearer. I am extremely grateful to those who stood by and prayed for me all these years,” she added. (AP)