MANILA, Philippines - Supreme Court justices should waive their judicial privilege and reveal what they know about the circumstances behind alleged irregularities in the release of a temporary restraining order on the travel ban against former President Gloria Macapagal Arroyo, a senator said Monday.

Senator-judge Alan Peter Cayetano, in an interview with ANC, cited exceptions to confidentiality in the courts, such as cases involving judicial misconduct.

"I think we all agree naman na impeachment is judicial misconduct pagka chief justice pinag-uusapan natin," he said.

The Supreme Court en banc, in a 12-0 vote, earlier denied the examination and reproduction of confidential court records of cases cited in the impeachment case against Chief Justice Renato Corona as subpoenaed by the Senate.

"They [Justices, officials and court employees] are subject as well to the disqualification by reason of privileged communication and the sub judice rule... these rules extend to documents and other communications which cannot be disclosed," the 28-page high court resolution read.

"These privileges, incidentally, belong to the Judiciary and are for the Supreme Court (as the representative and entity speaking for the Judiciary), and not for the individual Justice, judge, or court official or employees to waive," it added.

"Under the law... the Members of the Court may not be compelled to testify in the impeachment proceedings against the Chief Justice or other Members (Justices) of the Court about information they acquired in the performance of their official function of adjudication, such as information on how deliberations were conducted or the material inputs that the Justices used in decision-making, because the end-result would be the disclosure of confidential information that could subject them to criminal prosecution," it said.

"Such act violates judicial privilege (or the equivalent of executive privilege) as it pertains to the exercise of the constitutional mandate of adjudication," it added.

The Senate impeachment court also earlier denied the prosecution's motion to subpoena 4 Supreme Court justices to testify on Article 3 of the impeachment complaint.

However, the winds shifted in Article 7, wherein the dissenting opinions of Associate Justice Maria Lourdes Sereno are being used by the prosecution to show how Corona allegedly worked behind the scenes to ensure that the TRO on the Arroyo travel ban is issued by the high court.

Senator-judge Antonio Trillanes IV asked the impeachment court on Thursday to allow a written interrogation of Sereno.

Cayetano said the senator-judges will discuss the issue in a caucus on Monday.

"On Monday, pag-uusapan namin, how to get the testimony of some of the justices," he said.

"I'm also aware the Supreme Court is watching," he added.

Cayetano, however, expressed concern that some justices who want to come forward may fear sanctions at the hands of their colleagues.

"Sometimes, if someone goes out of their way, iyon pa ang pag-iinitan," he said. "So I'm hoping there will be justices from both sides, the majority and the minority in this issue, who will be willing to share what happened, without violating their rules."

He said he is willing to give up his right to ask clarificatory questions to a Supreme Court justice or will agree that only impeachment court presiding officer and Senate President Juan Ponce Enrile will only ask the questions from a judge who will be willing to take the witness stand.

"At the end of the day, I'd like to know the whole truth and not just the partial truth from the defense or the prosecution," he said.

"Ngayon kasi, very very clear, ito ang sinasabi ni Justice [Antonio] Carpio, kapag mayroong judicial misconduct, kasama din ito [exception to judicial privilege," he added.

"Unless we get the whole picture and some of the justices here [will appear as witnesses], we will have to rely on what the prosecution has already presented or what the defense will present," Cayetano said.