MANILA — Davao City Mayor Sebastian “Baste” Duterte was declared a hostile witness on Tuesday after taking the witness stand in the impeachment trial of his sister, Vice President Sara Duterte.

Duterte arrived at the Senate on the morning of September 29 for Day 31 of the proceedings. The House prosecution panel called him to testify under Article II of the impeachment complaint, which includes allegations involving the Vice President’s unexplained wealth, asset disclosures and business interests.

His appearance centers on records of transactions between the Davao City government and GenCorp Industries Inc.

The Vice President listed GenCorp as a business interest in her 2024 and 2025 Statements of Assets, Liabilities and Net Worth. However, Securities and Exchange Commission records previously presented in the impeachment proceedings did not identify her as an incorporator, director or stockholder of the company.

Mayor Duterte had originally been subpoenaed to appear from September 28 to 30. On Monday, he asked the impeachment court for more time to gather, organize, authenticate and reproduce the documents required by the subpoena.

Presiding officer Sen. Francis “Chiz” Escudero granted the request and allowed him to appear on September 29 and 30.

The subpoena directs the mayor to produce certified and electronic copies of Davao City government records involving GenCorp and other specified entities. Prosecutors sought his testimony to authenticate the city records and answer questions about the local government’s transactions with the company.

During Tuesday’s proceedings, the prosecution asked the impeachment court to treat Duterte as a hostile witness.

Escudero granted the request, saying the mayor’s adverse interest had been established.

“The adverse interest of the witness has been established,” Escudero said in declaring Duterte a hostile witness.

The designation allows prosecutors to ask leading questions during their examination. It does not, by itself, constitute a finding of wrongdoing against the witness.

The GenCorp transactions had already been examined a day before Duterte’s testimony.

Philippine Government Electronic Procurement System Division Chief Rendell Sopeña told the impeachment court that PhilGEPS records covered 15 contracts between Davao City and GenCorp worth ₱34.216 million.

Four of those contracts went through public bidding, while 11 were awarded through negotiated small-value procurement.

Those figures differ from an earlier statement by Mayor Duterte, who said the city had 19 transactions with GenCorp worth more than ₱33.2 million. He said four went through competitive public bidding while 15 used small-value procurement.

Sopeña stressed during his testimony that his knowledge was limited to records contained in the PhilGEPS system and that his testimony did not determine whether any procurement transaction was unlawful.

The prosecution is presenting the GenCorp records as part of its evidence under Article II. The defense has disputed the prosecution’s interpretation of the corporate and procurement records presented in the trial.

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