Top Biden adviser Steve Ricchetti said Wednesday that questions about former President Joseph R. Biden’s mental decline while in office advanced “baseless assertions” about his age, and there was no conspiracy during his presidency to hide it.

Mr. Ricchetti, former counselor to the president, appeared voluntarily for a transcribed interview with the House Oversight and Accountability Committee as part of the probe into Mr. Biden’s mental decline and his administration’s use of the autopen.

“There was no nefarious conspiracy of any kind among the president’s senior staff, and there was certainly no conspiracy to hide the president’s mental condition from the American people,” Mr. Ricchetti said in a prepared statement submitted to the committee.

Mr. Ricchetti described himself as one of the former president’s closest aides, who served alongside him for 13 years. He said the congressional investigation is “an obvious attempt to deflect from the chaos of this [Trump] administration’s first six months” and an “unprecedented” use of legislative procedure.

A source familiar with his testimony said Mr. Ricchetti said that aides close to Mr. Biden, who was 82 when he left office, knew his age was an issue and “were dealing with it as a political matter.”

Mr. Ricchetti told the Oversight panel Mr. Biden was fit enough to have run for president in 2024 and would have won a second term. He described Mr. Biden’s gaffes, many of them made in public, as “common mistakes” that had not increased since he served as vice president.

Mr. Ricchetti compared Mr. Biden’s cognitive missteps to those that President Clinton made when he was 45 years old, a source familiar with his testimony said.

In his prepared statement to the panel, Mr. Ricchetti insisted the concerns over Mr. Biden’s cognitive decline, many of them detailed in tell-all books by anonymous ex-Biden aides, created a “false narrative about the Biden presidency.” 

The source familiar with Mr. Ricchetti’s closed-door interview said he was “combative and defensive” and often “filibustered.”

He is one of many former Biden aides to be summoned to answer questions for the House probe. 

Some others chose not to appear voluntarily and were instead subpoenaed by Oversight Chair James Comer, Kentucky Republican, among them Dr. Kevin O’Connor, Mr. Biden’s former physician; Anthony Bernal, former first lady Jill Biden’s chief of staff; and Annie Tomasini, a longtime aide to Mr. Biden who served as senior adviser and deputy chief of staff toward the end of Mr. Biden’s term.

All three refused to answer questions and invoked their Fifth Amendment right against self-incrimination. 

The former president issued a statement in June denying he had his aides use the autopen to sign important documents without his knowledge.

“Let me be clear: I made the decisions during my presidency,” Mr. Biden said. “I made the decisions about pardons, executive orders, legislation, and proclamations. Any suggestion that I didn’t is ridiculous and false.”

• Mallory Wilson can be reached at mwilson@washingtontimes.com.