MANILA (REUTERS) - A Philippine senator and the biggest critic of President Rodrigo Duterte filed a "test case"before the Supreme Court on Monday (Nov 7), seeking to fend off what she called harassment by the volatile leader and his public tirades against her.

Ms Leila de Lima, the former justice minister who Mr Duterte's allies removed as head of a Senate probe into his bloody war on drugs, said she had filed a writ of "habeas data" against the president to protect her privacy and if successful, it could take away some of his immunity.

"This is a test case, a novel case of transcendental importance," Ms De Lima told reporters. "Habeas data is rarely invoked. We are testing the doctrine of presidential immunity."

In her petition, Ms De Lima wanted to stop Mr Duterte and his associates from collecting information about her private life and for evidence already gathered to be destroyed.

She also wants the court to stop the outspoken president making public statements that malign her as a woman and, according to the petition, "degrade her dignity as a human being".

Mr Duterte has verbally attacked de Ms Lima almost daily, during which he has accused her sexual impropriety, among other things.

She faces allegations she had close links to big drug dealers operating in prisons when she was a minister for six years under the previous government.

The move to unseat her as head of the Senate investigation into Mr Duterte's deadly campaign against drugs was launched by Mr Manny Pacquiao, a senator better known for his boxing prowess, including his unanimous victory over Jessie Vargas in Sunday's (Nov 6) WBO light welterweight bout in Las Vegas.

After her removal, Mr De Lima herself became subject of a probe, by Congress. The probe heard allegations that 70 per cent of country's drugs deals took place in a jail under her control.

Presidential spokesman Ernesto Abella said Ms De Lima was"playing the gender card" and her move was calculated to"generate media noise to drown out the accusations against her".

"By portraying herself as a victim, she seeks to distance herself from the intimate relationships which were also intertwined with drug trafficking," Mr Abella said.