Joe Biden has sued Donald Trump's Justice Department to block the release of audio recordings he made with his ghostwriter, material that investigators later used to question his mental competency.

The former president's latest legal action, lodged on Tuesday in federal court, comes just weeks before the DOJ's planned release of the explosive tapes and transcripts to Republican lawmakers and the conservative Heritage Foundation group. 

Biden held private conversations with biographer Mark Zwonitzer in 2016 and 2017 at his home while writing his memoir Promise Me, Dad, which chronicled his decision to consider a presidential run as his eldest son, Beau, had brain cancer.

The roughly 70 hours of recordings were later obtained by Special Counsel Robert Hur during his investigation into Biden's handling of classified documents. 

The probe determined that Biden read classified material out loud to Zwonitzer but recommended against prosecution because Biden's declining memory would make it difficult to prove he had acted willfully. 

The recordings were central to Hur's bombshell find in February 2024 that the 81-year-old was 'an elderly man with a poor memory.' The explosive characterization landed in the middle of Biden's re-election campaign and ignited speculation over his fitness to serve a second term. 

The recordings capture Biden telling Zwonitzer on tape, 'I just found all the classified stuff downstairs,' and, according to Hur's report, the former vice president read journal entries containing classified intelligence 'nearly verbatim' on at least three occasions. 

Court filings have also revealed Zwonitzer deleted some of the audio after learning of Hur's appointment as special counsel in 2023, however, investigators later recovered the material.

Trump reacted on Truth Social to Biden's attempt to keep the tapes under wraps by branding his predecessor 'A Crooked Politician!!!'

Biden's legal team argued the release of the tapes would amount to 'an unwarranted invasion of President Biden's privacy.'

'Every American, including a sitting or former vice president, has a right to privacy in the personal conversations he has within his own home,' Biden's attorneys wrote. 

Biden's legal team argued that when the Justice Department obtains private information through a criminal investigation, it must shield that material from public disclosure.

The tapes at issue are distinct from Hur's own interview of Biden, which the former president has also fought to keep from being publicly released.

Although Hur's investigation recommended no charges, it was damning for Biden during his reelection effort in 2024 against Trump. 

The Biden probe was launched in January 2023 after classified documents from his time as vice president were discovered at his former Washington office and his home in Wilmington, Delaware. 

Then-Attorney General Merrick Garland reacted by appointing Robert Hur as special counsel.

Material taken from Biden's home included classified documents concerning US military and foreign policy in Afghanistan, as well as notebooks containing Biden's handwritten entries on national security and foreign policy.   

Despite Biden's mishandling of classified material, the special counsel recommended against charges, writing that the former president would 'present himself to a jury, as he did during our interview of him, as a sympathetic, well-meaning, elderly man with a poor memory.'

Hur added, 'it would be difficult to convince a jury that they should convict him — by then a former president well into his eighties — of a serious felony that requires a mental state of willfulness.'