MANILA—Incumbent Makati City Mayor Abigail "Abby" Binay on Saturday said her brother and election rival Junjun Binay has accused her and her husband of being involved in the killing of his long-time aide.

Junjun appeared to lose his cool during an election forum held inside a church on the same day, after Abby urged candidates to stop spreading lies while campaigning.

• WATCH: Junjun, Abigail Binay feud spills over into church-organized poll forum

"Nag-aakusa siya sa akin tungkol sa asawa. Adik daw o meron kami kinalaman sa pagpatay sa sekretarya niya," Abigail said.

"Hindi dapat ganu’n ang klase ng kampanya. Basta ang sabi ko sa kanya, ikaw ang nag-umpisa. He must be hearing things because I didn’t say anything after that. Nag-freak out siya. I was just sitting there."

Junjun's aide, Monaliza "Monette" Bernardo, died on March 23 after being shot by unidentified motorcycle-riding assailants at her home in Barangay Olympia, Makati City, 2 days prior.

• Junjun Binay's long-time aide dies from gunshot wound

Abby, meanwhile, apologized to parishioners following her heated argument with Junjun in the middle of the forum organized by the Pastoral Council for Responsible Voting (PPCRV) at San Ildefonso Parish.

"I would like to apologize to PPCRV. Gusto natin sa simbahan kasi gusto natin mag-behave," she said.

"Kung may supporters na hindi nag-behave ako na nag-a-apologize," she added, addressing the cheers and boos her brother received after addressing the audience following their squabble.

Abby said she and her brother hadn't seen each other until Saturday.

"This is the first time that I met him. Hindi ko siya nakita noong (Makati election) peace covenant," she said.

"First time tapos we were seated in very close proximity."

Junjun earlier said Abby was screaming at him.

“Sinisigawan ako, inaangilan ako. Anyway ’wag na natin pahabain," he told ABS-CBN News.

Their father, former vice-president Jejomar Binay, said he was dismayed at his children's behavior and that he will deal with them.

“Nagpupuntahan sila doon kaya nagpunta na rin ako . . . Cool lang. Di maganda ’yun,” the elder Binay said, adding, “Ako na bahala doon,” when asked whether he would talk to his children.

—With reports from Kevin Manalo, ABS-CBN News