Dr. Kevin O’Connor, the former personal physician to President Joe Biden, invoked the Fifth Amendment (right to not self-incriminate) on Wednesday during a closed-door deposition before the House Committee on Oversight and Accountability. O’Connor refused to answer questions as part of an ongoing congressional investigation into Biden’s cognitive health while in office.

House Oversight Chairman James Comer, R-Ky., called Dr. O’Connor’s refusal to testify “further proof” of a broader cover-up to hide the former president’s alleged mental decline.

Former Rep. Mary Peltola is on record saying that Biden was one of the sharpest people she had met in DC.

“Dr. O’Connor took the Fifth when asked if he was told to lie about President Biden’s health and whether he was fit to be President of the United States,” Comer said. “It’s clear there was a conspiracy to cover up President Biden’s cognitive decline.”

The inquiry has gained new momentum following Biden’s recent disclosure that he had been battling an aggressive form of prostate cancer that had metastasized to his bones, a fact kept from the public until May, when it was disclosed the cancer had become serious.

On the same day as O’Connor’s deposition, government watchdog Protect the Public’s Trust filed a formal complaint with the D.C. Board of Medicine, calling for an investigation into the physician’s handling of Biden’s diagnosis and questioning whether O’Connor violated medical ethics.

“Physicians and other healthcare professionals must comply with strict standards of behavior,” PPT said in its filing, citing medical board rules that prohibit willfully filing false records, misrepresenting treatment, or demonstrating a careless disregard for a patient’s welfare, even if no harm occurs.

The watchdog’s complaint points to a series of public statements from the White House over the course of Biden’s presidency, which portrayed the president as healthy and mentally fit. That narrative persisted even as questions abounded among medical professionals and the American public regarding his visible signs of frailty, his trips and falls, and his constant verbal bumblings.

The matter is of greater importance in the context of the hundreds of autopen orders, pardons, and proclamations made by Biden during the time period in question.

Adding weight to the debate is testimony from former White House physician and Professor of Medicine Lawrence C. Mohr, who has emphasized that the role of a White House doctor involves unique ethical challenges. “They have a responsibility to the president as an individual patient and a responsibility to the nation,” Mohr has said. “The nature of these dual responsibilities confront White House physicians with a variety of unique issues, including presidential disability, implementation of the 25th Amendment, and a president’s right to privacy versus the public’s right to know.”

While the White House traditionally summarizes the president’s annual physical exam, there is currently no legal requirement for full disclosure of medical records.

Republicans have renewed calls for legislation requiring greater transparency, citing the lack of legal safeguards as a loophole ripe for abuse.

“Congress must assess legislative solutions to prevent such a coverup from happening again,” Comer said. “We will continue to interview more Biden White House aides to get the answers Americans deserve.”

With both a congressional investigation and a formal ethics complaint now in motion, pressure is growing on former administration officials to address lingering questions about what the public wasn’t told about Biden’s health.