Warning: Video contains offensive language.

(2nd UPDATE) OLD GRUDGES. Presumptive President Rodrigo Duterte on Sunday dubbed the Catholic Church as the "most hypocritical institution" as he lambasted its bishops for supposedly attempting to erode public support for him before the May 9 elections.

Duterte told reporters in Davao City that the Catholic Bishops' Conference of the Philippines (CBCP) released a pastoral letter a few days before the elections in a bid to dissuade the electorate from voting for him.

READ: CBCP to voters: 'Reject morally reprehensible bet'

Despite this, Duterte said he still won the presidential elections, which he described as a "public referendum" between him and the bishops. The long-time mayor of Davao City has a 6.2 million lead over administration candidate, Mar Roxas, going into the official canvassing of the results by Congress this week. Three of his four rivals have conceded.

"They campaigned against me, everybody was saying 'Do not vote for Duterte.' Fine. I said, let this election be a referendum between me and the Catholic Church... Sabi ko, this will be a referendum kung sinong tama sa atin. Look, were you able to stop me? Iilan lang kayong mga obispo diyan," he said.

In an apparent reference to Duterte, the CBCP on May 1 urged the public to reject a "morally reprehensible" candidate who has shown "scant regard" for the rights of others and the teachings of the Church.

CBCP President Lingayen-Dagupan Archbishop Socrates Villegas has previously criticized Duterte for cursing Pope Francis, whose visit caused heavy traffic in Metro Manila in January 2015, and for the mayor's statements on killing criminals.

Duterte, whose civil marriage to Elizabeth Zimmerman is annulled, has openly admitted to being a womanizer. He has also been at odds with human rights advocates for his alleged involvement in the Davao Death Squad and for his tough stance on criminals.

He has also made no secret his experience as a child supposedly molested by a priest. During the campaign, he revealed his alleged experiences following the furor caused by his cursing of Pope Francis.

Duterte also castigated a bishop who suggested that he should just file a case against his molester. He said he found this ridiculous.

“Paano ako mag-file? Yung pari died 30 years ago and the incident happened during the 50s. Saan ka makahanap ng venue, ang prescirtpion is about 20 years? Sinong idemanda ko? At sino ang accused?” he said.

'SINS OF THE CHURCH '

During Sunday's early morning press conference, Duterte said Catholic Church leaders should not hold themselves morally superior because their "hypocritical institution" has a long history of wrongdoing.

He also challenged the bishops to a debate so that he can expose, before assuming office on June 30, these alleged sins of the church.

"You have been castigating me or criticizing me -- you want a debate before I become president? Okay! Sinong...lahat ng bishops d'yan, tumindig kayo. I will tell you the sins of the Catholic Church beginning from the time the institution of the papacy was established," Duterte said.

"I will lecture until June 29 the sins of the Catholic Church, and whether or not you are still relevant. Alam mo, the most hypocritical institution is the Catholic Church," he added.

The incoming 16th Philippine president also said he can name bishops who allegedly took mistresses.

"If I start to name the bishops who got married or about the women in their lives, sasabog itong [simbahang] Katoliko," he said. "Do not think you are the moralizing agents of the society. As long as you are a human being, you are going to fall down... You're all pageantry."

He criticized priests and bishops who ask for favors from him and other politicians, recalling how certain bishops were heavily criticized for asking money from the Arroyo administration so they could buy SUVs.

Some of the bishops had admitted to having expensive cars, saying they used these vehicles to go to far-flung areas. They were later tagged later as “Pajero bishops”.

This, Duterte said, amounts to graft and corruption, and also violated the principle of separation of Church and State.

"Panahon ni Arroyo naghingian kayo... That is graft and corruption, hindi niyo alam 'yan, plus separation of church and state," Duterte said.

"Iyung ibang tao sa Pilipinas walang makain, walang medisina and you were enjoying the money of the god**** people of the Philippines by riding on that. Hindi na kayo nahiya n'yan. P******** kayo."

Duterte, who has been Davao City mayor for over 20 years, said Catholic leaders have also approached him for various requests.

"You ask so many favors even from me. I can show you the letters... 'Pag mayroon kayo, hingi dito, hingi [doon] tapos kung magsalita kayo, kayo lang ang marunong," he said.

Duterte maintained, however, that he believes in God, but he does not need religion to show his faith.

"I have this deep, abiding faith in God but that does not mean that you have to have a religion, you have to follow somebody, that you have to get a message from this and that," he said.

"Why would I have to go to a human being to whisper my sins and ask for forgiveness from him? Who are you to listen to my sins and give me absolution? You are not God."

After winning the presidential elections, the Duterte camp said the mayor planned to go to the Vatican to personally apologize and meet the Pope and He has since dropped this plan, saying it would be an exercise in duplicity since he already sent an apology letter to Pope Francis.

- With reports from Rodirey Salas, Dharel Placido, ABS-CBN News