Government prosecutors Thursday dropped charges against Ericson Acosta, a poet and cultural activist who has been in jail for two years on suspicion of being a communist rebel.
The Justice Department said it found "numerous irregularities" in the arrest and detention of Acosta, 40.
The National Union of People's Lawyers, which has been defending the poet, hailed the decision.
"It brings some renewed hope that dogged pursuit of justice and persistent efforts to right a wrong can still be rewarded," said Edre Olalia, the group's secretary-general.
"We hope that the many who are politically persecuted or thrown in jail on false or fabricated charges through legal shortcuts and hocus-pocus and made to indefinitely wait in anguish will get their own well deserved freedom," Olalia said.
Justice Secretary Leila de Lima said Acosta cannot be released from jail in the central Philippine city of Calbayog until the court acts on a motion to withdraw information on the case.
Acosta has claimed to have been "physically and psychologically tortured," deprived of sleep, intimidated and forced to admit being a member of the the communist led New People's Army.
In November 2011, at the Freedom to Create awards festival in Cape Town, South Africa, Acosta was among the finalists for the Imprisoned Artist Prize, along with nominees from Myanmar and Tibet.