MANILA, Philippines -- Sen. Leila de Lima’s supposed lover, who allegedly collected money from drug personalities to support her senatorial bid, may turn witness against her, President Rodrigo Duterte said Thursday.

“He (lover) can become a witness. Why would I file a case?” Duterte told reporters in Cotabato City when asked why cases have not been filed against de Lima’s married driver who is allegedly having an affair with her.

“I can use many people. I can use a prisoner. I can use her lover who is her driver,” he added.

Duterte believes de Lima has no one to blame but herself for the expose.

“She created the scandal. She knows she is a public official,” the president said.

Asked to react to de Lima’s appeal for him to spare her family, Duterte replied: "If you are in public office de Lima, your life is an open book."

Duterte insisted that he did not go overboard when he revealed supposed private details about de Lima, who has been critical of his war against illegal drugs.

“I did not, but she did. She accused policemen of a lot of things. P*t**g in*, the policemen are dying,” the president said.

Previous reports identified de Lima’s alleged lover as Ronnie Palisoc Dayan. Duterte alleged that de Lima had built a house for Dayan, whom he also accused of being involved in narcotics.

"Here is an immoral woman, flaunting well of course in so far as wife of the driver was concerned, it’s adultery. Here is a woman who funded the house of her lover and yet we do not see any complaint about it,” the president said in a speech delivered in Camp Crame on Wednesday. He has yet to show proof of the allegations.

The bungalow house allegedly built by De Lima for Dayan is located in Barangay Galarin in Urbiztondo, Pangasinan, The STAR reported on Wednesday.

President's lawyer: She had it coming

Malacañang officials were also quick to justify Duterte’s tirades against de Lima.

Chief Presidential Legal Counsel Salvador Panelo said Duterte was angered by de Lima’s allegations that he was behind the extrajudicial killings in Davao City.

“She (de Lima) had it coming. She has been repeatedly warned because she was defaming the president,” Panelo said.

“Remember, the information given by President Duterte is in relation to her being a public (official)… So that encompasses within the duty of the president to serve and protect the people and to inform the state of the nation of whatever is being done by the government officials and whatever situation we are in now,” he added.

Despite criticisms that the president was being misogynistic when he criticized de Lima, Panelo said there is no need for Duterte to apologize for his statements.

“Under the Constitution, all public officials are accountable to their acts. So if you do an illegal act or an act which is contrary to the demeanor of a public official, then you open yourself to criticism,” Panelo said.

Panelo also claimed that the attacks against de Lima were not meant to silence Duterte’s critics.

“Many have expressed opposition to the president’s policies but he (Duterte) did not say anything about them. I think what the president is saying is if you want to appear as righteous, you better be sure that what you’re doing from the very start is righteous, too,” he said.

When reminded that Duterte himself had two partners, Panelo replied: “He never denied having girlfriends. He was open to the public. Besides, he is a bachelor. He has not committed any crime.”

Duterte’s marriage with his former wife Elizabeth Zimmerma has been annulled. De Lima's marriage has likewise been annulled.

Presidential Spokesperson Ernesto Abella said Duterte did not like de Lima’s approach when she linked the spate of killings with his war on drugs.

“(The president) is appalled by Senator De Lima’s history of jumping to conclusions about the president’s culpability without sufficient evidence, lack of appreciation of the magnitude of the menace and taking the opportunity to grandstand in spite of the gravity of the situation,” he said in a statement.

De Lima, in a privilege speech at the Senate in support of her call for an investigation into drug-related killings, did not say that Duterte was responsible for the deaths and said that she supported the government's campaign against illegal drugs. She said, however, that basic rights must be upheld.

"We still have a system of law that processes and punishes wrongdoers. We have our Bill of Rights that accord the right to be presumed innocent. What is worrisome in this situation is that the war on drugs is becoming a convenient pretext for misguided or utterly corrupt law enforcers to kill just any one," she said earlier this month.

De Lima also wrote Duterte asking him to monitor the hearings, scheduled for Aug. 22 and 23. She said that there were indications that not all the deaths are related to the government's war on drugs and assured the president that they are not working at cross-purposes.

Presidential communications secretary Martin Andanar said Duterte’s tiff with de Lima has become a “national telenovela.”

“He (Duterte) has immunity. We do not have immunity on this table, neither do you have immunity. So if you say something that is libelous, then you can go to jail because you are not the President of the Republic,” Andanar said in a press conference in Davao City.

“The president fully understands his power, the power of immunity,” he added.

On Wednesday, Duterte claimed that the money collected by de Lima’s driver at the National Bilibid Prisons (NBP) in Muntinlupa came from illegal drugs and may have been used to fund her senatorial bid last May.

He admitted though that he could not tell yet whether de Lima was aware about her lover’s activities in the NBP.

De Lima has been vocal in criticizing Duterte’s crackdown on illegal drugs and has vowed to probe allegations of human rights abuses by law enforcers, some of which have already been filed at the Commission on Human Rights.