WikiLeaks founder Julian Assange will plead guilty to a felony charge in a deal with the U.S. Justice Department that will resolve a long-running legal saga that spanned multiple continents and centred on the publication of a trove of classified documents, according to court papers filed late Monday.

In a statement Monday, WikiLeaks said Assange had left a British prison on Monday and flown out of the United Kingdom from London Stansted Airport.

“After more than five years in a [two-by-three-metre] cell, isolated 23 hours a day, he will soon reunite with his wife Stella Assange, and their children, who have only known their father from behind bars,” the statement said.

“This is the result of a global campaign that spanned grassroots organisers, press freedom campaigners, legislators and leaders from across the political spectrum, all the way to the United Nations.”

Assange is scheduled to appear in the federal court in the Mariana Islands, a U.S. commonwealth in the Western Pacific, to plead guilty to an Espionage Act charge of conspiring to unlawfully obtain and disseminate classified national defence information, the Justice Department said in a letter filed in court.

The guilty plea, which must be approved by a judge, brings an abrupt conclusion to a criminal case of international intrigue and to the U.S. government’s years-long pursuit of a publisher whose hugely popular secret-sharing website made him a cause célèbre among many press freedom advocates who said he acted as a journalist to expose U.S. military wrongdoing.

Investigators, by contrast, have repeatedly asserted that his actions broke laws meant to protect sensitive information and put the country’s national security at risk.

He is expected to return to Australia after his plea and sentencing, which is scheduled for Wednesday morning, local time in Saipan, the largest island in the Mariana Islands. The hearing is taking place there because of Assange’s opposition to traveling to the continental U.S. and the court’s proximity to Australia.

The deal ensures that Assange will admit guilt while also sparing him from any additional prison time. He had spent years hiding out in the Ecuadorian embassy in London, after Swedish authorities sought his arrest on rape allegations, before being locked up in the United Kingdom.

Long fight to avoid extradition

Prosecutors have agreed to a sentence of the five years Assange has already spent in a high-security British prison while fighting to avoid extradition to the U.S. to face charges, a process that has played out in a series of hearings in London.

Last month, he won the right to appeal an extradition order after his lawyers argued that the U.S. government provided “blatantly inadequate” assurances that he would have the same free speech protections as an American citizen if extradited from Britain.

Assange has been heralded by many around the world as a hero who brought to light military wrongdoing in Iraq and Afghanistan. Among the files published by WikiLeaks was a video of a 2007 Apache helicopter attack by American forces in Baghdad that killed 11 people, including two Reuters journalists.

But his reputation has also been tarnished by rape allegations, which he has denied.

WATCH | Stella Assange slams ongoing prosecution of WikiLeaks founder:

Stella Assange slams ongoing prosecution of Wikileaks founder

The Justice Department’s indictment unsealed in 2019 accused Assange of encouraging and helping U.S. Army intelligence analyst Chelsea Manning steal diplomatic cables and military files that WikiLeaks published in 2010. Prosecutors had accused Assange of damaging national security by publishing documents that harmed the U.S. and its allies and aided its adversaries.

The case was lambasted by press advocates and Assange supporters. Federal prosecutors defended it as targeting conduct that went way beyond that of a journalist gathering information, amounting to an attempt to solicit, steal and indiscriminately publish classified government documents. It was brought even though the Obama administration Justice Department had passed on prosecuting him years earlier.