Former president Rodrigo Duterte has urged his supporters not to interfere in his case before the International Criminal Court (ICC), Vice President Sara Duterte said.

Speaking on behalf of her father, the Vice President said the older Duterte had conveyed this statement to his lawyer as she could not meet him on Friday, March 28, for his birthday as this date was reserved for her sister Veronica and the latter's mother Cielito "Honeylet" Avanceña.

"Sinabi niya na huwag tayo makialam sa kanyang kaso sa International Criminal Court (He asked us not to interfere in his case before the ICC)," she said.

The arrested former president said his legal team and the court should handle the proceedings without outside influence. He likewise advised his supporters not to discuss the case publicly.

"Kung gusto ninyo ipahayag ang inyong pagsuporta... ang inyong galit na nararamdaman o kung kasiyahan... sabi niya, huwag natin pag-usapan ang kaso (If you want to express your support, anger, or happiness, he said we should not talk about the case)," the Vice President said.

"Lalong-lalo na pagdating sa mga complainants o reklamo na nandyan sa loob sa International Criminal Court (Especially when it comes to the complainants or complaints filed before the ICC)," she added.

Instead, the former president asked his supporters to support the PDP-Laban senatorial candidates and guest candidates for the upcoming May elections.

Vice President Duterte revealed that her father had planned several campaign rallies for these candidates prior to his arrest and subsequent surrender to the ICC on March 11.

"Sinabi niya, ipaabot sa inyo na kailangan niya ang tulong (He said to let you know that he needs your help)," she said, noting that Duterte could no longer campaign for his candidates.

Former president Duterte is in ICC custody for crimes against humanity following the deaths and human rights violations during his administration's infamous drug war.