Sen. Leila de Lima on Saturday marked the first year of her detention at the Philippine National Police detention center in Quezon City.
Ahead of the anniversary of her arrest, the Senate minority and various rights groups called on the Philippine government to release her immediately.
The Department of Justice initially charged De Lima for drug trading, but over the months, the state prosecutors filed motions to amend the charges and indict the senator on conspiracy to commit drug trading instead.
De Lima is known as one of the most outspoken critics of President Rodrigio Duterte's administration.