The US Congress has released the transcript of testimony by former Special Counsel Jack Smith, in which he defended his decision to lead two defunct criminal investigations into Donald Trump.

The transcript, released on New Year's Eve by the House Judiciary Committee, is 255 pages. It features questions from lawmakers, and Smith's robust defense of his attempts to prosecute Trump for illegally retaining classified documents after leaving office, and his alleged attempts to overturn the 2020 election.

Trump pleaded not guilty in both cases, and the prosecutions ended after his re-election.

Since returning to office, Trump has demanded investigations of officials who criminally charged him.

The release also features video of Smith's nearly eight hours of deposition testimony, which took place behind closed doors earlier this month.