Vice President Leni Robredo on Friday called Senator Leila De Lima's arrest as "the latest move in a persistent campaign of political harassment."
"With contradicting testimonies from criminals as basis of the case, they circumvented due process to fast track the issuance of the arrest warrant," Robredo said in a statement.
The vice president, who is a part of De Lima's Liberal Party, said moves to discredit De Lima started after the lady senator "launched an investigation into the issue of extra judicial killings under the present administration."
Robredo urged Filipinos to "religiously" follow how the government will handle De Lima's case, and to "fight for the right to speak dissent."
"Our history as a nation is marred by instances where government officials use the processes of criminal justice to cow, silence, and eliminate critics," she said.
"We must make sure that our government institutions remain uncorrupted and independent of each other, particularly when it comes to checks and balances in pursuit of accountability," she added.