A Donald Trump-appointed US prosecutor has been accused of political motivation in his report on President Joe Biden’s handling of classified documents.

Former US Special Counsel Robert Hur faced a grilling from the Republican-led House of Representatives Judiciary Committee on Tuesday, which has been one of the panels conducting an impeachment inquiry into the 81-year-old Democratic president.

Hur – who was appointed as the former top federal prosecutor in Maryland by Biden’s predecessor and election rival, Republican Donald Trump – said he “did not exonerate” the president.

He noted that the investigation uncovered evidence that Biden knowingly kept secret documents after leaving the vice presidency in 2017.

Trump is facing four upcoming criminal trials, including on federal charges that he also retained classified documents after leaving the White House.

However, unlike Biden, he is charged with obstruction for trying to stop the government from collecting them.

Hur defended his discussion of Biden’s memory, saying the president’s state of mind was relevant to whether he committed a crime.

“My assessment in the report about the relevance of the president’s memory was necessary and accurate and fair,” Hur said.

“I did not sanitise my explanation. Nor did I disparage the president unfairly. I explained to the attorney general my decision and the reasons for it. That’s what I was required to do.”

Some Democrats argued that Hur’s discussion of Biden’s memory was unnecessary and inappropriate. Representative Adam Schiff suggested Hur was aware his analysis would have a “maximal political impact.”

Reuters/Ipsos polling shows that almost four in five Americans, including a large majority of Democrats, believe Biden is too old to work in government. A little more than half of respondents said that of Trump, 77.

“You must have understood the impact of your words,” Schiff said, accusing Hur of making a “political choice.”

Hur said politics played no part in his report, which drew anger from the White House after he released it last month.

A transcript of Hur’s interview with Biden reviewed by Reuters, conducted last October as Biden grappled with the fallout from Hamas’s October 7 assault on Israel, showed the president brought up the issue of his memory first.

“I’m a young man, so it’s not a problem,” Biden said jokingly to Hur when the prosecutor said he’d be asking questions about events that happened years earlier, the transcript showed.

The transcript showed Biden gave freewheeling answers to many of Hur’s questions, but struggled to recall certain details, including when he left the vice presidency.

Biden, the oldest person to hold the office of the US president in history, lashed out against the characterisations made in public remarks after the report’s release, saying his memory was fine, and Vice President Kamala Harris called the report politically-motivated.

Hur was appointed as a US attorney by Trump and made special counsel by Biden’s Attorney General Merrick Garland after Biden’s documents surfaced. His appointment ended on Monday, the department said.

—AAP