SYDNEY (Reuters) - Australian prosecutors have discontinued mining magnate Andrew Forrest's criminal prosecution of Meta over what he said were thousands of scam cryptocurrency advertisements on Facebook that feature his face.

The decision is a setback for Forrest, the 37% owner of iron ore producer Fortescue Metals Group and Australia's second-richest person, in his quest to hold the internet giant accountable for the ads. A separate civil lawsuit he has filed against Meta over the ads in California is ongoing.

A spokesperson for the Commonwealth Director of Public Prosecutions said on Friday that the department had found there was insufficient evidence to continue the prosecution, but did not elaborate.

Forrest has accused Meta of breaking Australia's anti-money laundering laws by allowing third-party scammers to use its software and platform to advertise fake cryptocurrency schemes that feature photos of his face, leading people to believe he had endorsed them.

He had pursued the lawsuit under Australian laws that allow an individual to criminally prosecute a foreign corporation with the consent of the attorney general.

Forrest said in a statement that the decision to dismiss the case was "a tragedy for innocent parents and grandparents who have lost their life savings."

A Meta spokesperson said scams were a complex threat, perpetrators use every available platform and "our sympathy goes out to people who have been impacted".

"Meta doesn't want scams on its platforms and we will continue to work tirelessly to prevent them and protect our users," the spokesperson said.

Forrest added that he would continue to pursue the California case, in which he accuses the U.S. firm of taking insufficient steps to prevent the advertisements.

In a filing for that case, Forrest said Meta promised him in 2019 that it would help remove the scam advertisements featuring his face, but that the ads kept appearing for Australian Facebook users, resulting in hefty losses for people who were duped.

The social media giant has argued that a U.S. law exempts internet platforms from responsibility for content posted by third parties and has sought to have Forrest's lawsuit dismissed. Forrest contends that Meta's argument is invalid, arguing that the U.S. law only applies domestically.

From April 2023 to November 2023, more than 1,000 such advertisements appeared on Facebook, Forrest's filing said.