Detained Senator Leila de Lima on Monday thanked retired Senior Associate Justice Antonio Carpio for continuing to ask for her release, after calling her detention "one of the grossest injustices ever perpetrated in recent memory."

"[President] Duterte and his lackeys may be successful in keeping me unjustly detained, but they failed to destroy how credible and respected personalities like Justice Carpio – who has unfailingly upheld judicial independence in his years in Supreme Court – view my unjust detention,” she said in a statement from her detention cell in Camp Crame.

"I am grateful for Justice Carpio’s firm stand against the injustice done to me, a manifestation of his belief in my innocence. Indeed, no amount of lies from a tyrant can erase the truth and stop it from prevailing,” she added.

De Lima, who won a seat in the 2016 senatorial election, was indicted based on testimonies of high-profile convicts who claimed she received around P10 million in drug payoffs during her time as justice secretary.

The senator has denied the allegations, saying they were politically charged.

De Lima and Carpio were part of the Philippine legal team in the historic battle against China over the West Philippine Sea dispute before an international arbitral tribunal, which the Philippines won.

Carpio voted with the minority in the 9-6 Supreme Court ruling in October 2017 which upheld the arrest warrant issued against De Lima by a Muntinlupa court on drug charges.

In his dissenting opinion, Carpio described the accusations against the lady senator as "blatantly a pure invention."

"This Court, the last bulwark of democracy and liberty in the land, should never countenance such a fake charge," he said.

“The Information glaringly does not charge the non-bailable offense of illegal trade of drugs since not a single essential element of this particular offense is alleged in the Information. What the Information actually charges is the bailable offense of direct bribery. Yet petitioner is held without bail."

“Worse, direct bribery falls under the exclusive original jurisdiction of the Sandiganbayan, not the RTC that issued the Warrant of Arrest that keeps petitioner under detention for the non-existent, non-bailable offense of illegal trade of drugs as charged in the present Information."

Last week Carpio told ANC's Headstart the cases against de Lima have no basis.

"As I wrote in my dissent, she should be released because the cases against her have no leg to stand on,” he said.

Carpio retired from the Supreme Court on his 70th birthday last Oct. 26 after 18 years of service.