House prosecution panel member and Manila 6th District Rep. Joel Chua said the possible appearance of "Mary Grace Piattos" as a witness in the impeachment trial of Vice President Sara Duterte could determine whether the name refers to a real person or a fictitious identity allegedly linked to confidential funds.

Speaking to DZBB on Friday, Chua said the prosecution considers the issue surrounding "Mary Grace Piattos" one of the matters that should be resolved during the trial.

"If no 'Mary Grace Piattos' appears, then it would support our theory that the person is fictitious," Chua said.

He added that if the defense presents a person using the name, the prosecution would seek to determine whether it is the person's real name or an alias.

"This is one of the issues that we will resolve in the impeachment trial," Chua said.

The lawmaker also pointed to the volume of acknowledgment receipts tied to confidential funds, noting that around 4,000 receipts could potentially be examined. He said the identities of the actual recipients of the confidential funds have yet to be disclosed.

Chua likewise discussed the prosecution's request involving a sealed box of tax records submitted by the Bureau of Internal Revenue (BIR).

According to Chua, the prosecution asked the impeachment court to allow the box to be opened, but the defense sought time to comment on the request.

The prosecution also moved to have the sealed box formally marked as evidence, a motion opposed by the defense. The impeachment court is expected to rule on both matters.

Chua said the contents of the BIR records are intended to strengthen the prosecution's evidence.

"It will only bolster our theory that her declared income does not match," he said.

Chua said his role within the House prosecution panel focuses on issues involving alleged unexplained wealth and the use of confidential funds.