"The Defense confirms that we filed our Comment to the Prosecution's Manifestation/Motion before the Impeachment Court," Poa said.
He added that the defense would not discuss the contents of its filing.
"In keeping with the Senate Rules on Impeachment, we will refrain from discussing the merits of our filing in public," he said.
House prosecutors on Wednesday asked the Senate impeachment court to open the sealed box containing the tax records of Vice President Sara Duterte and her husband for marking as evidence during the pre-trial conference.
Before the defense submitted its comment, prosecution spokesperson Lanao del Sur Rep. Zia Alonto Adiong suggested that the defense's objection to the marking of the BIR documents indicated it was apprehensive about what the records could reveal.
In response, Poa said it was improper to draw conclusions while the defense had yet to submit its position before the impeachment court.
He also stressed that motions filed by either party are for the impeachment court—not the clerk of court—to resolve.
"First and foremost, it must be emphasized that the Clerk of Court does not have the authority to rule on any motion made by either of the parties. Such matters are solely for the Impeachment Court to resolve," Poa said in an earlier statement.
Adiong had maintained that the BIR records would merely show tax payments, assets and liabilities, saying the documents could help establish the facts at issue.
He also questioned whether the defense was "afraid of the truth" and described the unopened BIR box as potentially containing significant evidence.
The impeachment court has yet to rule on the prosecution's motion.