Several senator-judges on Tuesday raised concerns over the timing of the National Bureau of Investigation's (NBI) announcement that it would investigate alleged irregularities in the construction of the nearly P10-billion sports complex at New Clark City for the 2019 Southeast Asian (SEA) Games, suggesting it could have a "chilling effect" on the ongoing impeachment trial of Vice President Sara Duterte.

During the trial, Senator Robin Padilla questioned whether the NBI's announcement was merely coincidental, noting that it came a day after Senator Alan Peter Cayetano criticized NBI Director Melvin Matibag for seeking to postpone his scheduled testimony before the impeachment court.

Padilla also cited other recent developments involving senator-judges, including cases filed against Senators Jinggoy Estrada and Rodante Marcoleta and Ombudsman actions involving himself and Cayetano.

"Should we be worried? Aren't we a free court with the constitutional authority to conduct these proceedings?" Padilla said in Filipino.

Cayetano, who chaired the Philippine Southeast Asian Games Organizing Committee (PHISGOC) for the 2019 Games, denied any wrongdoing and said he was not opposed to an investigation but objected to the manner and timing of the NBI's announcement.

"If the intention was to have a chilling effect, we already have that chilling effect," Cayetano told the impeachment court.

He argued that the NBI could have quietly conducted its investigation instead of publicly announcing it days before Matibag's scheduled appearance as a witness in the impeachment trial.

"But is it unfair to me and unfair to the court that just as he's about to be called as a witness on Monday, he announces an investigation? ... Don't announce it because it affects the integrity of the court," Cayetano said.

The senator maintained that the infrastructure component of the New Clark City sports facilities was handled by the Bases Conversion and Development Authority (BCDA), not the organizing committee he chaired.

He also disputed allegations that the project involved anomalous "congressional insertions," noting that he had already resigned as foreign affairs secretary to run for Congress when the funding was approved.

Cayetano further defended the 2019 SEA Games, saying the event brought honor to the country and produced world-class sports facilities.

"Our athletic and aquatic centers in Clark are among the best in the world," he said, adding that if anomalies were discovered, "I would be the first to get angry."

Senator Pia Cayetano echoed concerns that the NBI's public announcement could be perceived as an attempt to pressure members of the impeachment court.

"There is no jurisdiction in the world that allows a judge to be pressured and intimidated," she said.

Pia Cayetano questioned why the NBI director publicly announced the investigation instead of simply conducting it, saying the move distracted senator-judges from their constitutional duty.

"What's the purpose? Is he trying to intimidate us not to ask him tough questions when he is our resource person next week? I do not know. But those statements, those actions are not acceptable," she said.

The NBI earlier announced that it would investigate alleged irregularities in the construction of the P10-billion sports facilities at New Clark City, which were built for the Philippines' hosting of the 2019 SEA Games. The announcement came ahead of Matibag's scheduled testimony before the Senate impeachment court.