Acting Mayor Sebastian Z. Duterte officially takes his oath of office, by law of succession, as Mayor of Davao City at the Davao City Hall on January 23, 2026. Photo courtesy of Davao City PIO/File
MANILA (UPDATED) – Davao City Mayor Sebastian “Baste” Duterte is expected to take the witness stand in the impeachment trial of his sister, Vice President Sara Duterte, on Monday, Sept. 28, with the House prosecution panel saying it is prepared to question him as a hostile witness.
House lead prosecutor Rep. Gerville Luistro said Saturday the prosecution expects to finish its examination of the younger Duterte in an hour or less, since the remaining questions will mainly involve cross-examination.
“Sigurado kami na kaya ng isalang si Mayor Sebastian Duterte, [kasi] cross na lang ‘yung natira. So it will take maybe an hour or less or even less,” Luistro said.
The Senate impeachment court issued a subpoena ordering Baste to appear from September 28 to 30.
His original appearance was moved after the court had to accommodate unfinished testimony from a Securities and Exchange Commission witness and oral arguments on the disputed voting threshold.
Baste’s office received the subpoena on September 22, and was ordered to bring Davao City government records involving GenCorp Industries Inc. and corporations operating Jollibee branches from 2020 to the present.
GenCorp was among the companies declared by Vice President Sara Duterte as a business interest in her 2024 and 2025 Statements of Assets, Liabilities and Net Worth.
Baste: No ‘Duterte’ name in GenCorp documents for Davao City deals
The Davao City government has acknowledged 19 contracts with GenCorp worth P33.2 million. Baste has said neither his sister’s name nor the Duterte surname appears in the relevant city government contracts.
‘SANA DUMATING’
Luistro said the prosecution intends to present Baste as a hostile witness because of what she described as his interests being adverse to the prosecution’s position.
“Ultimately I want to clarify, he will be presented as a hostile witness sapagkat we appreciate that his interest is completely adverse to the position of the prosecution,” she said.
“Sana dumating siya para magkaroon ng kaliwanagan. Itong issue ng mga testimony that was provided by field jeps, kailangan nating mabigyan ang pagkakataon si Mayor Sebastian Duterte to answer those allegations.”
Prosecution spokesman Rep. Zia Alonto Adiong shared Luistro's sentiment, stressing that they "expect [Duterte] to be present."
"We hope that Mayor Baste Duterte will appear because we already requested a subpoena, and I believe he has already been subpoenaed," Adiong also said during a news forum in Quezon City.
The prosecution earlier announced that it would seek to have Baste classified as a hostile witness, citing his connection to Davao City government transactions involving GenCorp.
Luistro, however, said the prosecution has received no confirmation from Baste that he will appear Monday.
“Kung may confirmation ba kami, wala po. As a matter of fact, wala naman tayong communication doon at all,” she said.
WHAT IF BASTE DOES NOT APPEAR?
Luistro said the subpoena remains effective and that Baste is legally required to appear before the impeachment court.
Baste Duterte can't say no to impeach subpoena, says Luistro
Sara Duterte yet to confirm attendance in brother Sebastian’s appearance in impeachment trial
“The subpoena is part of the compulsory power of the honorable impeachment court,” she said. “As a matter of fact, wala namang option na hindi dumating. The only option is dumating kasi compulsory power ‘yun.”
“Kung hindi dumating, the prosecution can consider moving for citing him in contempt,” she said.
The impeachment court itself may also act on its own initiative, including issuing another subpoena or a contempt order, according to Luistro.
“Whatever action they wish to take, pwede another subpoena,” she said. “Pwede naman on their own ay mag-issue sila ng order, contempt order.”
"Being a public servant and a mayor at that, he understands, I believe, the subpoena power of the Senate. As to whether or not he would go, that is entirely up to him. But on the enforcement of the subpoena power, he has to come," said Adiong, for his part.
"Otherwise, we don't want to preempt what would be the decision or the course of action of the Senate acting as impeachment court. What would be their response should Mayor Baste Duterte not heed the subpoena of the Senate? But we expect him to be there," he added.
Luistro said the next witness in line is expected to come from the Philippine National Police Firearms and Explosives Office (PNP-FEO).
“From the designation of the office of this witness, it is given already. So this has something to do with firearms of the respondent Vice President,” Luistro said.
The prosecution is also preparing to subpoena former Sen. Antonio Trillanes IV and may seek subpoenas for AMLAC and banks after the defense rejected its requests for admission of common exhibits, Luistro said.
The testimony of these witnesses forms part of the prosecution’s presentation for Article 2 of the Articles of Impeachment, which accuses Duterte of unexplained wealth, including alleged SALN violations and failure to divest from business interests while serving as Vice President.
Three witnesses to testify on VP Duterte unexplained wealth allegation
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