Swedish prosecutors on Tuesday announced they were dropping a rape investigation into WikiLeaks founder Julian Assange after a review of the evidence.

While the complainant's evidence was deemed credible and reliable, witnesses' memories had faded after almost a decade, Deputy Chief Prosecutor Eva-Marie Persson said.

"After conducting a comprehensive assessment of what has emerged during the course of the preliminary investigation, I then make the assessment that the evidence is not strong enough to form the basis for filing an indictment," Persson said at a news conference.

The prosecutor said the decision could be appealed.

Assange, 48, has been fighting the potential charges since August 2010, when an investigation was launched after two women accused him of sexual offenses during a visit to Stockholm.

Assange, who has always denied the allegations, then fled to the United Kingdom and eventually took up residency in London's Ecuadorian Embassy. He spent seven years holed up in the embassy before he was dragged out in April.

The Swedish investigation was discontinued in 2017 while Assange was living in the embassy, but it was reopened shortly after he lost his asylum.

The Australian national is currently in a U.K. jail, where he is serving a 12-month sentence for skipping bail in 2012, when he was fighting extradition to Sweden in connection with the same case.

The United States is seeking his extradition so he can face charges relating to the release of hundreds of thousands of classified military documents provided by former Army intelligence officer Chelsea Manning.

In May, the Department of Justice indicted Assange on 17 new charges under the Espionage Act, which critics say has potential free speech implications.

Kristinn Hrafnsson, WikiLeaks editor-in-chief, said the organization was now switching gears to deal with the charges Assange is facing in the U.S.

“Let us now focus on the threat Mr Assange has been warning about for years: the belligerent prosecution of the United States and the threat it poses to the First Amendment,” he said.

An extradition hearing to decide whether Assange should be sent to the U.S. is scheduled for February next year.