A judge has dismissed the criminal case accusing Donald Trump of illegally holding onto classified documents.

Florida-based US District Aileen Cannon, who was nominated by Trump, ruled that Special Counsel Jack Smith, who is leading the prosecution, was unlawfully appointed to his role and did not have the authority to bring the case.

The ruling is likely to be appealed by the prosecution.

It marked another legal victory for Trump, following the US Supreme Court ruling that as a former president he enjoyed immunity from prosecution for many of his actions in office.

The ruling is a victory for the former President

Courts in other cases have repeatedly upheld the ability of the US Justice Department to appoint special counsels to handle certain politically sensitive investigations.

But Justice Cannon’s ruling throws the future of the case, which once posed serious legal peril for Trump, into doubt.

Smith is also prosecuting Trump in federal court in Washington over his attempts to overturn the 2020 election, but his lawyers have not made a similar challenge to the special counsel in that case.

In the documents case, Trump was indicted on charges that he wilfully retained sensitive national security documents at his Mar-a-Lago social club after leaving office and obstructed government efforts to retrieve the material.

Trump is facing off against Biden in the polls in NovemberPA

Trump's Mar-A-Lago Resort

Two others, Trump personal aide Walt Nauta and Mar-a-Lago property manager Carlos De Olivera were also charged with obstructing the investigation.

Trump’s lawyers challenged the legal authority for Attorney General Merrick Garland’s 2022 decision to appoint Smith to lead investigations into Trump.

They argued the appointment violated the US Constitution because his office was not created by Congress and he was not confirmed by the Senate.